UK's missing 40,000 illegal immigrants

A senior official conceded that tens of thousands of migrants who should have left the country more than six years ago could still be here.

A trawl of files has uncovered “no ­formal record” of any of the illegals leaving the UK.

Whitehall staff have been ordered to delve through a vast backlog of case records to find out if any of them can be found and sent home.

The latest lapse was revealed in a letter to the Commons home affairs committee from UK Border Agency chief executive Lin Homer.

She admitted that files dating from before 2003 showed people who had failed to leave after their visas expired or had been refused permission to stay.

Police records are now being examined to see if any of them are potentially “harmful” to the public.

Critics last night accused Gordon Brown and Home Secretary Alan Johnson of presiding over “utter chaos” in our border control system.

Sir Andrew Green, chairman of the population think tank Migrationwatch, described the revelation as “Yet another skeleton in the Home Office cupboard.” He said: “This is symptomatic of the utter chaos in the asylum and immigration system during the past 10 years. Nobody in the private sector would get away with such a performance.”

Shadow Home Secretary Chris Grayling said: “This looks suspiciously as if the Home Office is trying to get rid of its problem cases by quietly abandoning them in the hope that no one is looking.”

Lib Dem spokes­man Chris Huhne said: “Needle in a haystack operations like this are the direct consequence of decades of mismanagement of our borders.”

Ms Homer said: “We believe many of these individuals will have either gone home, been re­moved or been grant­ed leave through a different route. We expect those here illegally to return home. Where they refuse to do so, we will seek to enforce their return.” But she admitted it might not be possible to expel them.

The blunder comes as the EU today announces moves to take control of Britain’s asylum system.