Inquiry into border force passport check claims
Home Secretary Theresa May is launching an independent inquiry into claims the UK border force ceased carrying out some passport checks during the summer.
It is alleged staff were told to relax identity checks on non-EU nationals.
Brodie Clark, head of the force and a board member of the UK Border Agency, has already been suspended over the allegations along with two others.
Shadow Home Office minister Chris Bryant attacked Mrs May for previously issuing "advice to cut corners".
The official investigation will be led by the Chief Inspector of the UK Border Agency, John Vine.
Mrs May will make a statement in the Commons about the allegations on Monday afternoon, the Home Office confirmed.
In July, the Home Office said EU national checks could be reduced in "limited circumstances".
'Incredulity and fury'
Ministers had agreed their biometric passports could be checked "upon the discretion of a UKBA official" instead of automatically.
It is now alleged Mr Clark told staff not to carry out checks on the passports of some people from outside the EU.
The Home Office said in a statement: "Brodie Clark is alleged to have authorised UKBA officials to abandon biometric checks on non-European Economic Area nationals, the verification of the fingerprints of non-EEA nationals and warnings index checks on adults at Calais."
The warning index checks - aimed at flagging up those who may be "of interest" to the border agency - were apparently only abandoned in Calais, but continued at other entry points.
BBC home affairs correspondent Tom Symonds said the Home Office did not know the precise extent to which checks were relaxed.
Home Secretary Theresa May's reaction to the allegations was "incredulity and fury", a source told the BBC.
However, Mr Bryant MP said: "It seems ministers' advice in July was to cut some corners because there was a shortage of staff.
"Theresa May can huff and puff as much as she wants and suggest that she's furious, but if the decision was hers about the numbers of staff or the cutting of corners then she's got to stand up and face the music."
Staff working for the UK border force are responsible for checking passports and conducting immigration raids.
Senior UKBA official Graeme Kyle, who is director of operations at Heathrow Airport, is one of the two others suspended.
Sue Smith, of the Public and Commercial Services Union, said job cuts had led to staffing shortages.
"The travelling public, understandably, want to have a fast and efficient service, and yet we are also under a reduced work force," she said.
But Mark Reckless, a Tory member of the Home Affairs Select Committee, dismissed the idea that the checks had been relaxed because of cuts to personnel.
"This reflects a culture of impunity at the top of the civil service and the fact that however badly civil servants mess up they are never sacked," he added.
Biometric passports contain a digital image of the holder's face which can be used to compare with the printed version and check the passport has not been forged.
On Friday, the Home Affairs Select Committee reported that 124,000 deportation cases had been shelved by UKBA.