Modern slavery data: Joint sector letter
Dear Ed Humpherson,
We are writing to ask you to investigate what we believe are breaches of the Code of Practice for Statistics by the Home Office between 2015 and 2021. These breaches are in relation to statistics on modern slavery and the National Referral Mechanism (NRM), the Government’s framework for identifying and potentially supporting victims of modern slavery.
Misleading use of official statistics
We understand the Office for Statistics Regulation (OSR) will intervene where “official statistics or data used in a document or statement are presented in such a way that… they are likely to mislead the public or undermine the integrity of official statistics”.
For this reason, we wish to raise a Home Office press release published on 20 March 2021, titled ‘Alarming rise of abuse within modern slavery system”. This release reported that “major increases in child rapists, people who threaten national security and failed asylum seekers” were “clogging up the modern slavery system” and claimed there was “an alarming rise in people abusing our modern slavery system by posing as victims in order to prevent their removal and enable them stay [sic] in the country”.
Immediately following this claim, and presented as evidence, the press release reported that “National Referral Mechanism referrals, the government’s system for identifying victims of modern slavery, more than doubled between 2017 and 2020 from 5,141 to 10,613”. These numbers are drawn from Home Office official statistics.
We believe this use of statistics is misleading, as an increase in NRM referrals does not, of itself, indicate fraudulent use of the system for identifying victims, and may simply indicate growing awareness of the system among first responders.
Secondly, even if NRM referrals were inherently suspect, the totals quoted would not support these claims, as the total does not differentiate between those with or without criminal convictions, those with convictions as a result of their exploitation, and those victims who have right to remain in the UK. In addition, UK nationals made up a larger proportion of NRM referrals in 2020 than 2017. UK victims were also included in the total provided.
The press release’s claims and statistics were subsequently reproduced in national newspapers including The Sun, The Telegraph and The Daily Mail.
Similar claims were repeated by the then-Home Secretary, Suella Braverman MP, at Conservative Party Conference on 4 October 2022, who said “our modern slavery laws are being abused by people gaming the system – we’ve seen a 450% increase in modern slavery claims since 2014”. This total is, again, inclusive of UK nationals and those with secure immigration status.
We believe this use of statistics by the Home Office and Home Secretary risks misleading a wide audience, and would be grateful for your intervention.
Refusal to provide data where requested
The Code of Practice for Statistics states that “The views received from users, potential users and other stakeholders should be addressed, where practicable… Feedback should be provided to them about how their needs can and cannot be met, being transparent about reasons for the decisions made and any constraints”, and “People in organisations that release statistics should… meet consistent standards of behaviour that reflect the wider public good”. 
We are concerned that Ministers may have been briefed to inform MPs and peers on multiple occasions that the Home Office does not hold important data on the outcomes facing modern slavery victims, and this has subsequently been shown not to be the case. Between 2015 and 2021, Parliamentarians were refused data on the immigration outcomes, detention and deportation of survivors of slavery on the basis that this information was not held centrally. However, requests via the Freedom of Information Act (FOIA) were later fulfilled via centrally-held databases. An investigation into the cause of this disparity is crucial, and we ask the OSR to clarify whether statistical producers were required to provide data in response to the below Parliamentary questions.
Example A: Data on the deportation of survivors
On 5 April 2019, Baroness Williams of Trafford asked in Parliament “how many victims of trafficking or modern slavery who have received a positive conclusive grounds decision have been removed from the UK” and was told “there is no central record of those who have received a positive Conclusive Grounds decision and later removed. The Home Office therefore does not collate or publish the data requested”.
However, on 30 May 2019, following a FOIA request to the Home Office, After Exploitation was supplied with data drawn from a “live operational database” on the number of individuals who had a positive Conclusive Grounds decision before being a subject of voluntary or enforced removal.
Example B: Data on voluntary removals from the UK
On 26 April 2019, Liz Saville Roberts MP asked how many potential victims of modern slavery referred to the NRM had been granted residency in the UK as a consequence of their exploitation and agreed to return to their country of origin, and was told “The specific information you have requested is not readily available and could only be obtained at disproportionate cost”.
However, on 8 January 2020, following a FOIA request to the Home Office, After Exploitation was supplied with a response that showed that the Home Office did hold data on the number of voluntary returns of modern slavery survivors.
Example C: Data on survivors held in immigration detention
On numerous occasions between 2015 and 2019, MPs asked the Home Office for information about the number of modern slavery survivors held in immigration detention:
- On 28 September 2015, Louise Haigh MP asked for estimates of the number of victims of trafficking who were detained in immigration detention and was told “This data is not collected centrally and accurate figures are not available”.
- On 14 October 2015, Kate Osamor MP asked how many victims of human trafficking had been detained in the last five years and was told “This data is not collected centrally and accurate figures are not available”.
- On 24 November 2015, Kate Osamor MP asked how many detainees held in Yarl’s Wood Immigration Removal Centre had been identified as victims of human trafficking and was told “This data is not collected centrally and accurate figures are not available”.
- On 24 June 2019, Frank Field MP asked how many people held in a immigration detention centre are recognised as victims of modern slavery and/or human trafficking, and was told “there is no central record of those who have received a positive Conclusive Grounds decision and are detained under immigration powers.
The Home Office therefore does not collate or publish the data requested”.
- On 22 July 2019, David Davis MP asked how many migrant detainees were referred to the NRM each year, and what proportion of migrant detainees referred to the NRM were subsequently given positive decisions by the Home Office that there were reasonable grounds to believe they were trafficked to the UK, and was told
“[available] data does not distinguish whether individuals are migrant detainees”. 
- On 25 October 2019, Chris Ruane MP asked for the number of victims of trafficking or slavery who have been subject to immigration detention in each year since 2010 and was told “[available] information does not distinguish between those detained under immigration powers and those living in the community”.
- On 4 November 2019, Alex Norris MP asked “what proportion of [NRM] referrals receive negative Reasonable Grounds decisions for people in immigration detention and people outside of immigration detention” and was told “[available] information does not distinguish between those detained under immigration powers and those living in the community”.
However, on 28 June 2019, following a FOIA request to the Home Office, After Exploitation was supplied with a response that showed that the Home Office was able to supply data from a “live operational database” on the number of individuals who were in detention in immigration removal centres and had a positive reasonable and conclusive grounds decisions (i.e. were also modern slavery survivors). There were 507 such individuals held in detention during 2018.
In a debate in Parliament on 17 July 2019, then-Immigration Minister Caroline Nokes MP was asked why the Government had refused to disclose data on the detention of trafficking victims, in the light of the response to After Exploitation. She told Parliament:
While that information may be obtainable from the live Home Office case information database, otherwise referred to as CID, the information would be for internal management only. For example, some data may be incomplete and freedom of information requests are heavily caveated as such. Releases of data from CID are always caveated and sometimes it is possible the data is not always accurate; there may be instances where individuals are counted twice. It is standard practice in parliamentary questions that we do not provide information that does not form part of published statistics.
We seek your guidance as to whether this answer and the answers above were in line with the Code of Practice for Statistics. We would also be grateful for clarification on whether the Minister was correct that it is standard practice not to provide information that is not part of published statistics. This is not mentioned in Cabinet Office guidance on answering Parliamentary questions24 and House of Commons guidance says MPs should not ask for “information included in easily accessible published sources (for example, departmental
Relevance to users
The Code of Practice for Statistics also states “Users of statistics and data should be at the centre of statistical production; their needs should be understood, their views sought and acted upon, and their use of statistics supported… Statistics producers should consider whether to produce new statistics to meet identified information gaps”.
Civil society, Parliamentarians, and researchers depend on modern slavery data to produce policy recommendations and effective advocacy for both Government and survivors. However, data on the support, immigration and criminal justice outcomes relevant to survivors does not form part of the NRM quarterly or annual statistics, and is inconsistently provided as part when requested via FOIA (as above). Currently, researchers have only have a relatively small public data offering to rely upon when it comes to modern slavery.
As stakeholders, we hope that you will use your powers as a regulator to emphasise the importance of improved data provision in the areas of modern slavery policy which the sector sees as key. These offerings include, but are not limited to, data relating to:
- Support access, such as disaggregated data on how many survivors can access which forms of support, which is routinely denied in FOI requests, although the Home Office compiles high-level information on this for its annual reporting
- Immigration outcomes, including how many survivors are subject to immigration control, or prison-like settings under Immigration Powers
- Redress access, such as acceptance rates for CICA and the frequency of court ordered compensation.
We are grateful for your attention, and look forward to your response.
Maya Esslemont, After Exploitation
Anna Powell-Smith, Centre for Public Data
Dr. Ruth Van Dyke, Bakhita Centre for Research on Slavery, Exploitation and Abuse
Prof. David Gadd, University of Manchester
Kamena Dorling, Helen Bamber Foundation
Elli Free, Room to Heal
Lesley Gladwell, Rebuild Project, East Midlands
James Wilson, Detention Action
Sian Summer-Rees, City of Sanctuary
Helen Hodgson, Hope at Home
Victoria Marks, Anti Trafficking and Labour Exploitation Unit
Mia Hasenson-Gross, Rene Cassin
Naomi Webb, Good Chance Theatre
Sonya Sceats, Freedom From Torture
Sarah Teather, Jesuit Refugee Service UK
Naeema Ahmed, AFRUCA Safeguarding Children
Naeema Ahmed, UK BME Anti-Slavery Network
Denise McDowell, Greater Manchester Immigration Aid Unit
Jamie Fookes, Anti Trafficking Monitoring Group
Philip Ishola, Love146
Rudy Schulkind, Bail for Immigration Detainees
Lucila Granada, Focus on Labour Exploitation
Marissa Begonia, Voice of Domestic Workers
James Wilson, Detention Action
 Office for Statistics Regulation, Our Interventions Policy.
 Home Office, Press release: Alarming rise of abuse within modern slavery system, 20 March 2021.
 Home Office, Modern Slavery: National Referral Mechanism statistics.
 820 of 5,145 referrals (16%) were UK nationals in 2017, while 3,560 of 10,613 referrals (34%) were UK nationals in 2020. Sources:
 The Sun, Child rapists and terrorists will be stopped from using exploiting modern slavery loophole to stay in Britain, 19 March 2021.
 The Telegraph, Modern slavery laws to be overhauled to make them harder for foreign criminals to exploit, 22 March 2021.
 The Daily Mail, Migrants are claiming they are victims of modern slavery to avoid deportation from the UK, 6 June 2021.
Number of suspected modern slavery victims hits new record, 11 August 2022.
 Home Secretary’s Speech, Conservative Party, 2022. https://www.conservatives.com/news/2022/our-plan-for-law-and-order
 Office for Statistics Regulation, Code of Practice for Statistics.
 Hansard, Slavery: Question for Home Office, 27 March 2019.
 FOI request and response, Deportation of human trafficking victims, May 2019.
 Hansard, Slavery: Victims: Question for Home Office, 8 April 2019.
 FOI request and response, Voluntary removals of potential victims of trafficking, January 2020.
 Hansard, Migrants: Detainees: Question for Home Office, 14 September 2015.
 Hansard, Human Trafficking: Detainees: Question for Home Office, 9 October 2015.
 Hansard, Yarl’s Wood Immigration Removal Centre: Human Trafficking: Question for Home Office, 17 November 2015.
 Hansard, Migrants: Detainees: Question for Home Office, 19 June 2019.
 Hansard, Migrants: Detainees: Question for Home Office, 11 July 2019.
 Hansard, Migrants: Detainees: Question for Home Office, 11 July 2019.
 Hansard, Human Trafficking: Question for Home Office, 17 October 2019.
 Hansard, Human Trafficking: Question for Home Office, 29 October 2019.
 FOI request and response, Detention of potential victims of trafficking, June 2019.
 Hansard, Immigration Detention: Victims of Modern Slavery, 17 July 2019. The debate appears to refer to the Parliamentary question of 24 June 2019, above.
 Cabinet Office, Drafting answers to parliamentary questions: guidance.
 UK Parliament, MPs’ Guide to Procedure: Information Readily Available.
 FOI request and response, FOI request – RNA outcomes, September 2021.
 HM Government, 2021 UK Annual Report on Modern Slavery (p37).
Mark Pont to John Marais: Statistics on modern slavery in the UK (March 2023)