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Immigration Detention in the UK

29 May 2019

This briefing provides an overview of immigration detention practices in the UK. It discusses the capacity of the UK’s detention estate, including the number of detainees, their characteristics, and lengths of detention. It also examines the detention of children and the overall financial costs of operating the estate.

  1. Key Points
    • Approximately 24,700 people entered immigration detention in the UK in 2018, 10% fewer than in 2017
    • From 2009 to 2018, the population of immigration detainees was between around 1,800 and 3,500, falling to a low of 1,784 in the last quarter of 2018
    • Around one-third of immigration detainees were held for longer than 28 days, from 2010 to 2018
    • Around half of those entering immigration detention have sought asylum in the UK at some point
    • In 2018, 63 children were detained for immigration purposes, down from around 1,100 in 2009
    • In the fourth quarter of 2018, it cost, on average, £87.71 per day to hold someone in immigration detention
  1. Understanding the Policy

    Immigration detention refers to the Home Office practice of detaining foreign nationals for the purposes of immigration control. Reasons for holding someone in detention typically include one or more of the following: to effect their removal; to establish their identity or the basis of their immigration or asylum claim; where there is reason to believe they will abscond if granted temporary admission or release on bail; or when release is not considered to be ‘conducive to the public good’. In some instances, the reasons for a person’s detention change while he or she is being held. All detentions end in removal or release to the community, on bail or otherwise.

    The Home Office has the discretionary power to detain a person at any point of their immigration process: upon arrival in the UK; upon presentation to an immigration office within the country; during a check-in with immigration officials; once a decision to remove has been issued; following arrest by a police officer; or after a prison sentence.

    Since detention is meant to be the final point before removal, immigration detainees are held mostly in Immigration Removal Centres (IRCs); Short-Term Holding Facilities (STHFs); pre-departure accommodation facilities (PDA); short-term holding rooms based at ports of entry; and prisons. Immigration detention forms part of an administrative process rather than a criminal justice procedure.

    According to Home Office policy and international law, “Detention must be used sparingly, and for the shortest period necessary”. The detention of an individual must be reviewed at least every month. Detention beyond this period must be authorised at certain levels of seniority within the Home Office. There is no upper time limit on how long a person can be detained.

    The UK’s Detention Estate

    As of April 2019, there are seven IRCs (Brook House, Colnbrook, Dungavel, Harmondsworth, Morton Hall, Tinsley House, Yarl’s Wood), two STHFs (Manchester Residential STHF, formerly Pennine House, and Larne House), one pre-departure accommodation facility, and 30 holding rooms.

    There are also short-term units within some IRCs, including at Colnbrook and Yarl’s Wood. Of the short-term holding rooms, 19 are at ports and airports, and 11 at reporting centres. There are 14 reporting centres in the UK, which under some circumstances released detainees must report regularly to. All of these facilities are in England, except for Dungavel IRC in Scotland, and Larne House STHF in Northern Ireland.

    Except for Morton Hall IRC, which is managed by the Prison Service, the Home Office has outsourced the management of its IRCs to private firms – MITIE, GEO, G4S and Serco. In 2011, the contract for managing the holding rooms, and two of the three STHFs, passed to Reliance (now Tascor).

    Several IRCs have been closed in recent years, as part of a planned reduction of the size of the detention estate. Dover and Haslar IRCs closed in 2015, The Verne closed in December 2017 (to be returned to its previous purpose as a men’s prison), and Campsfield House IRC was closed on 14 December 2018.

    Between 2011 and 2016, the Cedars Pre-Departure Accommodation operated in West Sussex, where the charity Barnardo’s oversaw welfare services delivered to families detained for short periods before removal. A ‘discrete self-contained unit’ at Tinsley House IRC opened to accommodate families in May 2017, with G4S now fully responsible for welfare services. Families can be held for up to 72 hours, with a ministerial declaration required to extend a family’s stay to no more than seven days in ‘exceptional’ cases. In 2016, it was announced that Dungavel IRC would close, though it still remains operative.

    EEA Nationals

    European Economic Area (EEA) and Swiss nationals have free movement access to the UK and are not generally subject to British immigration control. Despite the stronger protections afforded to EEA deportees under European Union legislation than are available to third-country nationals facing removal, EEA nationals can be detained in the UK, usually prior to deportation for criminal offending. The Immigration Act 2014 brought changes to the interpretation of Article 8 of the European Convention on Human Rights (the right to respect for one’s family and private life) in deportation cases, making it easier to remove foreign national offenders with families or long-term residence in the UK.

    Vulnerable People

    The impact of detention on vulnerable people has received increased attention in recent years.  An independent review by Stephen Shaw (2016) into the welfare of vulnerable detainees contained proposals to reduce their numbers. In response to these proposals, the Home Office revised its 2016 “Adults at risk in immigration detention” Guidance, introducing an Adults at Risk (AAR) policy. In his follow-up review (2018), Mr Shaw reported that it was not clear that AAR had made a significant difference to the number of vulnerable people in detention, but that it had “engendered a genuine focus on vulnerability”.

  1. Understanding the Evidence

    The publicly available data on immigration detention are found primarily in publications of the Home Office and Her Majesty’s Inspectorate of Prisons (HMIP). The Home Office’s published detention statistics relate only to those detained solely under Immigration Act powers, and not those detained for criminal purposes. The statistics also exclude those detained for less than 24 hours in short-term holding rooms at ports and airports, and in police cells.

    Data on those entering detention through prisons is included from Q3 2017 onwards, but do not include people detained in police cells and short-term holding rooms at ports and airports (for less than 24 hours), and those detained under both criminal and immigration powers and their dependants. As such, counts from before Q3 2017 are not comparable with those for earlier periods. A detainee will be recorded more than once if they been detained on more than one separate occasion in the relevant time period – for example, if they have left detention and then been subsequently re-detained.

    Data on those in detention relate to those in detention on the last day of the quarter.

    Asylum detainees relate to people detained solely under Immigration Act powers who are recorded as having claimed asylum at some stage, regardless of the outcome of the claim.

Approximately 24,700 migrants entered immigration detention in the UK in 2018, 10% fewer than in 2017

From 2009 to 2018, the number of people entering detention per year has ranged from approximately 25,000 to 32,000. There was a steady rise in people entering immigration detention from 2010 to 2015, followed by a steady fall from 2016 (Figure 1).

In the year ending December 2018, 24,748 migrants entered detention, down 10% on the previous year.

Figure 1

Of the 25,487 leaving detention, 44% (11,152) were deported from the UK to another country; 55% (13,945) were released on bail; 0.2% (47) were granted leave to enter or remain in the UK; and 1% (343) were either returned to criminal detention, released unconditionally, absconded, were sectioned under the Mental Health Act, or died in detention (Home Office, 2019c).

In recent years, NGOs have argued in favour of community-based alternative to detention programs, including greater use of bail for detainees. The proportion of people leaving detention through release on immigration bail has in fact increased over time, from 34% in 2010 to 55% in 2018.

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From 2009 to 2018, the population of immigration detainees fluctuated between around 1,800 and 3,500, falling to a low of 1,784 in the last quarter of 2018

The UK has one of the largest immigration detention systems in Europe (Global Detention Project, 2019). After the closure of The Verne, Dover, Cedars, and Campsfield House, the capacity of the immigration detention estate stood at around 3,200 (Shaw, 2018).

Since 2009, there have been between 1,800 and 3,500 migrants detained at any given time (Figure 2).

At the end of December 2018, the 1,784 people detained under Immigration Act powers, including in prisons, was the lowest number since comparable statistics have been available. The fall in numbers after 2015 will likely have resulted in part from the suspension of the Detained Fast Track policy, which from 2000 until July 2015 enabled the detention of asylum seekers if a quick decision on their case was likely; and from the closing of Dover IRC and Haslar IRC in 2015 (which accounted for approximately 600 places in combination), and The Verne IRC in 2017 (accounting for an additional 600 places).

Home Office analysis has suggested that further falls in the detained population in 2018 might have resulted from (1) the commencement on 15 January 2018 of Schedule 10 to the Immigration Act 2016, on Immigration Bail, which introduced automatic bail hearings for detainees four months after entering detention; and (2) changes to the immigration system following the Windrush situation (Home Office, 2019a). Post-Windrush changes included caseworker decisions being checked by colleagues, and increasing face-to-face contact time between caseworkers and detainees (Joint Select Committee on Human Rights, 2019).

Figure 2

Adults can also be detained in prisons. On 31 December 2018, 366 people were detained for immigration purposes in prisons.

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Around one-third of immigration detainees are held for longer than 28 days

There is no upper time limit for individual periods of immigration detention in the UK. From Q1 2010 to Q4 2018, of those leaving detention at the end of a given quarter, 65%, on average, had been detained for between 1 and 28 days, 17% for 29 days to under 2 months, 15% for 2 months to under 6 months, 5% for 6 months to under 1 year, and less than 1% had been detained for 1 year or longer.

In Q4 2018, 73% of those leaving detention had been held for 28 days or fewer (Figure 3).

Campaign groups have argued that both long detention lengths and the uncertainty of lengths of detention are harmful to detainees. Various actors such as HM Chief Inspector of Prisons (2017); the All Party Parliamentary Group on Refugees and the All Party Parliamentary Group on Migration (2015); and the House of Commons Home Affairs Committee (2019) have argued for a maximum 28-day limit on immigration detention.

Figure 3

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Around half of those entering immigration detention have sought asylum in the UK at some point

There are several categories of people who are detained under Immigration Act powers, and some individuals will fall into more than one category. These include: new arrivals awaiting examination by an immigration officer to determine their right to entry; new arrivals who have been refused permission to enter the UK and are awaiting removal; those who have either failed to leave the UK on expiry of their visas (visa overstayers), or who have not complied with the terms of their visas, or have attained their visas by deception; and people found in the UK who are awaiting a decision on whether they are to be removed, or pending arrangements for their removal. In some cases, long-term residents or British citizens who are unable to prove their nationality have been detained, as illustrated by the 2018 Windrush situation.

The largest category of immigration detainees is people who have sought asylum at some stage during their immigration process. In 2018, asylum detainees accounted for 51% (12,637) of people entering detention (Home Office, 2019c).

The number of EU nationals entering detention has increased over the past decade, reaching 4,185 in 2018, or 17% of all those entering detention (Figure 3).

Figure 4

The Migration Observatory’s policy primer on ‘Immigration Detention: Policy Challenges’ provides more analysis of these issues.

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In 2018, 63 children were detained for immigration purposes, down from around 1,100 in 2009

In the 1990s, the Home Office rarely detained families with children. However, between 2005 and 2009, non-governmental organisations and other groups estimated that the number of children detained with their families stood at up to 2,000 per year (Crawley and Lester, 2005; Sankey et al., 2010).

Home Office statistics record that 1,119 children entered detention in 2009. After a policy change under the Conservative and Liberal Democrat Coalition Government, and the opening of Cedars pre-departure accommodation near Gatwick in 2011, the number of detained children fell to 127 in 2011 (Figure 3), before reaching its lowest levels on record in 2017 and 2018, of 63.

Figure 5

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In the fourth quarter of 2018, it cost, on average, £87.71 per day to hold someone in immigration detention

The annual cost of detention for the year ending March 2018 was £108 million (Home Office, 2018). In addition, compensation is payable to people who have been wrongly detained. In the financial year 2016–17, there were 143 cases of such wrongful detention, for which £3.3m compensation was paid.

In the last quarter of 2018, the estimated average per-day cost of holding someone in immigration detention was £87.71 (Home Office, 2019b).

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Evidence gaps and limitations

There are three notable deficiencies in the available data on immigration detention in the UK. First, it is not possible to track individual trajectories of detention, release and re-detention through the statistics, because they are presented as separate numbers of occurrences. Second, there is a deficit in information about the nature of decision making by Home Office officials on when to arrest and detain, and when to release people from detention. This information would go some way towards illuminating the meanings of the official statistics. Third, the Home Office does not provide information on the reasons for people being placed into or held in immigration detention.

With thanks to Peter Walsh for help updating this briefing, and to Mary Bosworth, Ali McGinley, and officials at the Home Office for comments on an earlier version.


Related Material

Recommended citation

Silverman, S. J., & Griffiths, M. E. B. (2019). Immigration detention in the UK. Migration Observatory, COMPAS, University of Oxford, UK

  1. Media Coverage
    • Independent (26 Oct 2016)

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