Birmingham council's former chief executive has admitted she is to blame for a series of crises in the immigration service.
And Lin Homer, who became Director General of the Immigration and Nationality Directorate last August, revealed she had been given six weeks to sort out her department.
But she was forced to admit even more foreign criminals had been freed to walk the streets of Britain than previously thought.
Ms Homer was mauled by MPs as she gave evidence to the Home Affairs Select Committee, which is investigating the blunders which led to the resignation of Charles Clarke, the former Home Secretary.
There was a public outcry when it emerged that 1,019 foreign prisoners had been released from jail without being considered for deportation as they should have been.
But the errors continued even after Mr Clarke was sacked by the Prime Minister.
His successor, John Reid, told the committee at an earlier hearing that some of the most serious offenders were back in jail - but then had to apologise when officials told him they had actually received bail.
Ms Homer said: "To a degree I think you have to hold me responsible because I am in charge of the business."
However, she added: "I believe that clear knowledge of the full extent of the failure was only understood at a relatively junior level.
"I don't feel it is fair to place responsibility for issues such as this at a junior level."
She was put on the spot by MP David Winnick (Lab Walsall North), who asked whether senior immigration managers had let Mr Clarke down.
Ms Homer said: "I feel I let him down."
And she was forced to admit even more foreign criminals may have been freed, because the figure of 1,019 only applied to England.
She said: "We are undertaking some detailed work with Wales, Scotland and Northern Ireland to get the final total."
Ms Homer said she had been given until July 25 to report on progress improving the immigration service to Birmingham MP Liam Byrne (Lab Hodge Hill), the Immigration Minister.
Dr Reid had unwittingly misled the committee at an earlier briefing because he had received the wrong information from officials, she said.
He told the committee two weeks ago that a number of foreign offenders who were wrongly released without deportation being considered had been rounded up and were now under lock and key.
But in fact, 11 of them, including a murderer, a rapist and a paedophile, had been given bail.
Ms Homer said: "I deeply regret that and would apologise to you myself for that error of information."