Despite introducing significant changes to its enforcement activity, the Home Office cannot fully demonstrate that the actions of its Immigration Enforcement directorate are helping it to achieve its objectives, according to a report by the National Audit Office.

The Home Office’s vision for Immigration Enforcement is to “reduce the size of the illegal population and the harm it causes”. It supports this vision through its operational missions of preventing illegal migration through greater compliance with laws, tackling threats associated with immigration offending and maximising returns of the illegal population and foreign national offenders to their country of origin.1

The complex nature of immigration crime and offending presents a significant challenge for the Home Office. In trying to prevent, identify and remove immigration offenders, it must balance a broad range of responsibilities and respond to changing threats and risks to life, for example to those who try to enter the country by travelling in lorries or small boats.

The Home Office does not have an up-to-date estimate of how many people have no right to remain in the UK. Its last estimate was around 430,000 people in 2005. More recent estimates from other organisations suggest the population might have doubled, although the NAO has not validated these estimates. The Home Office estimates demand for immigration enforcement activity to be between 240,000 and 320,000 cases per year,2 but it does not know whether demand is growing or falling. It also has not consistently defined what constitutes “harm” caused by the illegal population and who it affects.

While the Home Office collects a large amount of performance data on its activities it does not allow it to demonstrate the impact of its work. For example, the NAO found that the Home Office is unable to assess whether its measures to prevent people from accessing government funded services have any meaningful impact on how likely a person is to return to their country of origin. Also, the Home Office is helping to stop more people from entering the country without proper documentation or through clandestine means, but it does not know whether this reflects detection of a higher proportion of attempts or if the number of attempts is increasing.

The Home Office has returned, or helped to return, just over 13,100 people without leave to remain in the 12 months to the end of November 2019, of which 5,600 people returned voluntarily. It encourages people to return voluntarily, but these returns have reduced, from an average of 1,200 a month in 2015 to approximately 460 in 2019. The Home Office has enforced the removal of 7,400 of the 13,100 immigration offenders returned in the 12 months to the end of November 2019. Almost 5,000 of those were foreign national offenders.3

Less than half of planned enforced returns (48%) by the Home Office went ahead during 2019, often as a result of late legal challenges to removal. As a result, it released 14,900 (62 per cent) of immigration detainees from immigration removal centres last year.4 It believes many of these late legal challenges are used to delay removal but did not provide any evidence that it has tried to actively understand and manage these challenges.

Despite the Home Office investing in new technology and improved working practices, the NAO found several examples of inefficiencies in Immigration Enforcement’s processes which meant that staff had to carry out additional work. This was often due to information being incorrect or out of date, or documents such as warrants or travel documentation arriving too late to enable action. Delays in progressing cases leave individuals waiting longer to hear their outcome. Immigration Enforcement does not systematically record these delays to identify where and how they can make improvements.

The Home Office is currently considering its response to the Windrush review5 and has commissioned a review of the wider border and immigration system. In responding to these reviews, the Home Office has an opportunity to address many of the issues the NAO has identified.

The NAO recommends that the Home Office develops a better understanding of how its efforts and activities affect the outcomes it is trying to achieve. This includes improving its knowledge of the scale of illegal migration and how cases flow through the immigration system.

“The work of Immigration Enforcement by its very nature is complex and challenging. While the Home Office has introduced significant changes to its enforcement activity, it cannot demonstrate that overall performance is improving.

“The Department needs a better understanding of the impact of its immigration enforcement activity on its overarching vision to reduce the size of the illegal population and the harm it causes.”

Gareth Davies, head of the NAO

Read the full report

Immigration enforcement

Notes for editors

  1. The report uses the term 'illegal population' to describe all those who have entered the UK unlawfully, those who entered lawfully but have remained in the UK without having the right to do so, and those foreign nationals who have committed serious or repeated criminal offences (foreign national offenders) within the UK and need to be removed. This is the term the Home Office uses.
  2. Demand is defined as the number people with no leave to remain that are known through contact with the Home Office, law enforcement organisations or other government departments. This includes people who it detected entering the country illegally, people who are known to have remained in the country following expiry of a visa or were refused asylum.
  3. Figures do not add due to rounding.
  4. The Home Office detains some individuals before they return to their country of origin. It has significantly reduced the size of its detention estate since 2016, reducing its costs by £40m (21%), and is detaining people for a shorter time.
  5. In the spring of 2018 the Department faced criticism over its treatment of the Windrush generation. The government consequently commissioned an independent review of lessons to be learned from the Department's actions. This review was published in March 2020 and the Department committed to providing a formal response within six months.
  6. Press notices and reports are available from the date of publication on the NAO website. Hard copies can be obtained by using the relevant links on our website.
  7. The National Audit Office (NAO) scrutinises public spending for Parliament and is independent of government and the civil service. It helps Parliament hold government to account and it use its insights to help people who manage and govern public bodies improve public services. The Comptroller and Auditor General (C&AG), Gareth Davies, is an Officer of the House of Commons and leads the NAO. The NAO audits the financial accounts of departments and other public bodies. It also examines and report on the value for money of how public money has been spent. In 2018, the NAO’s work led to a positive financial impact through reduced costs, improved service delivery, or other benefits to citizens, of £539 million.

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