Senior sources on the Daily Mirror privately acknowledged yesterday that the newspaper had serious problems with its publication of photographs purporting to show British soldiers abusing Iraqi prisoners.
But they said the newspaper's editor, Piers Morgan, was preparing to "front it out" in the hope that the news agenda would move on and he could save his job.
The House of Commons Defence Committee announced last night that it would be calling Mr Morgan to give evidence to an inquiry into the brutality allegations.
Amid widespread scepticism over the veracity of the pictures - allegedly of a British soldier beating and urinating on an Iraqi civilian - Mr Morgan is facing calls to resign if the images are shown to be fakes.
One minister said: "They don't look genuine. But we are determined to get to the bottom of this. If it turns out that soldiers are guilty of wrongdoing, that is a very serious matter. That is why we need the full co-operation of the Daily Mirror. Piers Morgan has a duty to name his sources for these allegations."
Mr Morgan was in ebullient mood yesterday, saying he would be happy to appear before the Commons committee. "I have nothing to hide, and stand completely behind our story, so I have no problem talking to anyone about it frankly," he said. "Not one new fact has emerged to expose our pictures or story as a fake, nothing. Until or if it does, we are very relaxed about it and very confident about the outcome of the investigation."
Sources at the Mirror took a different view and compared the situation with previous gaffes made by the paper. "We are just hoping to brazen it out," one said, adding that Mr Morgan was a "past master" at toughing out such situations.
One colleague recalled how the editor had fought himself out of criticisms over a 2002 headline, "Mourn on the Fourth of July", which denounced the United States as "the world's leading rogue state" only months after the attacks on the World Trade Centre.
Mr Morgan was due to attend a newspaper awards ceremony at the London Press Club yesterday but was said to be unable to leave the office because he was too busy.
As belief continued to grow on other national titles that the Mirror has been tricked, the Conservative leader, Michael Howard, who was the guest speaker at the ceremony, dished out some torture treatment of his own to the cornered editor. Mr Howard spoke out after being asked whether he was comfortable with the newspaper proprietor Richard Desmond's decision to switch the allegiance of the Daily Express to the Conservatives.
The Tory leader said: "I'm a lot happier with the support of the Express Group of newspapers than I might be with the support of a certain other newspaper if certain inquiries turn out the way a lot of people think they will."
The Daily Express led the attacks on the Mirror pictures yesterday with a front-page article headlined "Shameful Truth". It claimed that soldiers - said by some reports to have been paid £10,000 for the story - had concocted the torture pictures after being asked to produce visual evidence to corroborate their initial allegations of maltreatment of Iraqis.
Mr Morgan tried to turn the tables on the Express by denouncing its article as "a complete fabrication". He said: "They have made it up, and it is not true."
He was also adamant that nobody inside his newspaper had lost confidence in the story. "The only people doubting the photos are rival hacks trying to create mischief and ex-soldiers trying to earn a few quid on TV saying, 'those floppy hats don't look right'," he said.
Mr Morgan - widely regarded as brilliant but error-prone - drew criticism in 1996 for a front-page headline that screamed "Achtung! Surrender" on the day of the England versus Germany Euro 96 semi-final match .
Mirror sources said the prisoner abuse issue was such a fast-moving story that the focus would soon move away from the photographs, purportedly supplied by two members of the Queen's Lancashire Regiment.
Bruce George, the Commons Defence Committee chairman, said: "The issue is of immense national and international interest. I don't know if the pictures were genuine or not. If they are genuine, there is great cause for concern.
"If the pictures turn out to be a spoof, the hoax of the century, the damage is done. But at least there will be the satisfaction of knowing that the regiment is not guilty."
Mr Morgan is an accomplished performer on such platforms. Last year, he faced the Culture Select Committee with apparent relish as MPs voiced criticisms of the standards of tabloid newspapers.
With the Mirror already facing claims that it has put the lives of British soldiers in danger, Mr Morgan - who comes from an Army family - is not likely to find his next parliamentary grilling so agreeable.