National Audit Office report looks at the work of the Home Office's Immigration Enforcement directorate

The National Audit Office (NAO) on Wednesday published a comprehensive report on the work of the Home Office's Immigration Enforcement directorate.

The 65-page report is here.

The NAO said: "This report assesses whether the Department is successfully delivering its stated missions and objectives to support its vision of reducing the size of the illegal population and the harm it causes."

Most media coverage of the report (such as BBC News, Sky News and the Guardian) headlined the finding that the most recent government estimate of the number of irregular migrants in the UK was produced 15 years ago.

The report states: "The Department's vision is to reduce the size of the illegal population and the harm it causes, but its understanding of the scale of these issues is mixed. Measuring a hidden population is intrinsically complex and will always include a degree of uncertainty. The Department has not attempted to estimate the total illegal population since 2005, when it believed the number to be around 430,000 people. More recent estimates from other organisations suggest there may be more than twice this number, although we have not sought to validate these estimates."

As noted by the Guardian, the NAO also found that the Home Office has no specific evidence to show that its hostile (or compliant) environment policies to discourage irregular migration are actually effective.

The NAO said: "The Department's view is that by removing the incentives which it believes draws people to the UK illegally, it can encourage voluntary departures, foster compliance with visa and passport conditions and encourage people to leave before their right to remain in the UK has expired. It also believes these measures act as a deterrent against those individuals who have not had contact with Immigration Enforcement or its partners. The Department acknowledges that it had no specific evidence base to support the effectiveness of these measures when they were introduced. It is currently unable to measure whether these activities have the desired effect of encouraging people to leave voluntarily."

Chai Patel of the Joint Council for the Welfare of Immigrants (JCWI) told The Independent: "The hostile environment, whether it works or not, causes so many other problems and needs to be got rid of, but the fact that they can't even tell us it's working is a damning indictment of where they are … It's a cultural statement, that's why it's a hostile environment. It's not about whether it works or not. It's one of the things they can talk about in terms of being tough on immigration."

Colin Yeo, Free Movement editor and Garden Court barrister, posted on Twitter: "Neither Home Office as an institution nor ministers are interested in whether the hostile environment 'works'. Same point was made previously by Chief Inspector in 2016 and 2018 reports and Wendy Williams earlier this year. It is a moral crusade not a policy."

In concluding, the NAO report found: "The Home Office's (the Department's) vision is to reduce the size of the illegal population, and the harm it causes, through missions to ensure greater compliance with immigration laws, tackle the threats of immigration offending and maximise the return of immigration and foreign national offenders from the UK. However, the complex nature of immigration crime and offending presents a significant challenge. For example, in trying to prevent, identify and remove immigration offenders, the Department must deal with a changing and varied threat from organised crime and a population which is, by definition, hard to interact with. The Department assesses its performance through a wide range of quantitative and qualitative measures. Where available, these measures show some positive developments in areas such as preventing illegal entry into the country and tackling organised crime, but performance against the crucial measure of returns has fallen. However, collectively, these measures do not provide a sufficient assessment of outcomes or an evidence base the Department can use to demonstrate the cumulative impact of its activities or judge overall success against its missions.

"The Department has made some progress in improving individual aspects of immigration enforcement but does not yet manage this as an end-to-end system. It has recently begun to develop its understanding of the people currently in its system, but it does not yet have a full understanding of how its activities affect the progress those people take through each part of the system. Without looking at the system, and what is actually being achieved, as a whole, the Department will not be able to demonstrate it is delivering value for money."

Sky News quoted a Home Office spokesman as saying: "We have taken back control of our immigration system and for the first time in a generation, we will have full control over who comes and stays here. As this report acknowledges, the nature of immigration crime and offending is complicated and we are consistently looking at ways to get ahead of the organised gangs behind it.

"We work tirelessly with international partners and agencies, such as the NCA, to tackle illegal migration, close down routes for people smuggling and return those with no right to remain in the UK wherever possible."