Senior ministers have rallied round beleaguered Home Secretary Amber Rudd after she admitted she should have known about official targets for removing illegal immigrants.
Labour and the SNP stepped up calls for her resignation following the leak of an internal Home Office memorandum suggesting she was informed of the targets, even though she had previously told MPs she was unaware of them.
But in a series of late night tweets on Friday, Ms Rudd said that although her office had been copied in to the document she did not see it herself.
She apologised for not being aware of the targets - including 12,800 "enforced returns" in 2017-18 - and said she would be making a Commons statement on Monday to address the "legitimate questions" which had been raised.
Her assertion that she did not see the memo - which was leaked to The Guardian - is crucial as, under the Ministerial Code, any minister who "knowingly" misleads Parliament is expected to resign.
However, it leaves her exposed to criticism that she has lost her grip on her department at a time when she was already under fire over her handling of the Windrush scandal.
Downing Street said she had the "full confidence" of the Prime Minister.
However, Labour said she was only being kept on to protect Theresa May who - as home secretary under David Cameron - was the architect of the "hostile environment" strategy for illegal immigrants which, it says, has led to some who were entitled to be in the country being threatened with deportation.
Shadow home secretary Diane Abbott told the BBC Radio 4 programme: "I am just surprised that she doesn't seem to take the issue seriously enough to offer her resignation.
Ms Abbott said it was the decision to set a "broad numerical target" for removals which had contributed to a situation where Commonwealth citizens who came to Britain in the decades after the Second World War were being wrongly told to leave.
"It wasn't saying, for instance, we have to have a target for deporting former criminals. The danger is that that very broad target put pressure on Home Office officials to bundle Jamaican grandmothers into detention centres," she said.
Environment Secretary Michael Gove led the defence of Ms Rudd, saying she was "a highly talented and highly effective minister" and accused Labour of trying to "weaponise" the issue.
"When documents that should be placed in front of a Home Secretary aren't then placed in front of a Home Secretary, that is sad, that is regrettable," he told the Today programme.
"But she was very clear both in her apology and also in the fact that this specific document wasn't placed in her box, wasn't brought to her attention."
Justice Secretary David Gauke said Ms Rudd was an "excellent" Home Secretary who had accepted she made a mistake.
"She didn't knowingly mislead the House of Commons, but she accepted that she was inaccurate in her statements," he told the BBC Radio 4 Today programme.
Cabinet Office minister David Lidington said Ms Rudd was dealing with "one of the biggest challenges in government", and that she had the "resourcefulness and determination" to get the job done.
The internal Home Office document, seen by The Guardian, refers to "a target of achieving 12,800 enforced returns in 2017-18", adding "we have exceeded our target of assisted returns".
It goes on to refer to the progress that had been made towards achieving a 10% increase in performance on enforced returns "which we promised the Home Secretary earlier this year".
The six-page memorandum, prepared by Hugh Ind - the director general of the Immigration Enforcement (IE) agency - last June, was said to have been copied to Ms Rudd as well as to Brandon Lewis, the then immigration minister, and a number of senior officials and special advisers.
Ms Rudd had initially denied the Home Office had targets for removals when she was questioned on Wednesday by a Commons committee investigating the Windrush fiasco.
However, after it emerged a 2015 inspection report made clear the practice did exist, she told MPs on Thursday that while the immigration arm of the Home Office had used "local targets", they were "not published targets against which performance was assessed".