THE UK Home Office has not made a proper assessment of the number of illegal immigrants over the past 15 years, reveals a new report.
The National Audit Office (NAO) said there were about 430,000 people in the country with no right to remain, according to the last official estimate in 2005.
The public spending watchdog, however, noted that subsequent independent research pegged the tally at over one million.
For instance, a Pew Research report in 2019 had said there were about 1.2 million illegal immigrants -- the highest estimate so far -- in the UK.
“The Home Office does not have an up-to-date estimate of how many people have no right to remain in the UK,” said the NAO report titled ‘Immigration Enforcement’ released on Wednesday (17).
"Although there would be significant uncertainty around any estimate it [the department] developed, such an estimate could help the department to demonstrate that its activities are effective in deterring attempts to enter or remain in the UK illegally."
The report said the Home Office had placed the demand for its immigration enforcement services between 240,000 and 320,000 cases a year.
This estimate, however, did not include people who had no governmental contact over the past two years and, hence, failed to "provide a baseline" to gauge if the department's enforcement measure were effective.
"Due to data quality issues, Immigration Enforcement cannot say whether the number of people 'genuinely putting a demand' on its activities is increasing or decreasing," the report said.
In the past year to October 2019, detected attempts by people to come into the UK by clandestine means increased to 46,900. However, the NAO said it was not clear if this was because more attempts were being made or if there was better detection.
The NAO said the Home Office should look at how other government departments threw up with estimates of "hidden activity", such as organised crime, to "improve its understanding of the full scale of the illegal population in the UK and identify new ways to address some of the challenges it faces".
Furthermore, it added, the Home Office was unable to assess whether its actions to stop ineligible people accessing government-funded services had “any meaningful impact on the likelihood that an individual will leave the UK voluntarily".
"Although there would be significant uncertainty around any estimate it [the department] developed, such an estimate could help the department to demonstrate that its activities are effective in deterring attempts to enter or remain in the UK illegally," the report said.
Noting that immigration enforcement was "complex and challenging", NAO chief Gareth Davies said: "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."
Labour MP Meg Hillier, who chairs the Commons Public Accounts Committee, said the report showed that the Home Office "has no idea how many people are in the country illegally and doesn't seem interested in finding out".
"It can't demonstrate that its actions to control illegal immigration are working as intended, and doesn't understand how different aspects of its work fit together," she added.
A Home Office spokesman maintained that the UK had "taken back control of our immigration system and for the first time in a generation" and "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," he said.
"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.
"We make no apology for seeking to deport foreign national offenders and since 2010 we have removed more than 53,000 criminals."
