Members of the defence select committee have ordered that Mirror editor Piers Morgan give evidence following the publication of photographs allegedly showing British troops torturing Iraqi prisoners.

It emerged yesterday that chief executive of Trinity Mirror, Sly Bailey, approved the decision to publish the images.

Speaking in the Commons, Tony Blair insisted that human rights abuses were "wholly unacceptable", but said it would be "extremely serious" if the pictures turned out to be fake.

Conservative leader Michael Howard argued that it would be a "matter of the utmost seriousness for which the editor of the Daily Mirror would have to take full responsibility".

Morgan continues to stand by the story.

Following publication of photographs featuring American troops, President Bush appeared on two Arab television stations to promise that those responsible would be "brought to justice", describing their behaviour as "abhorrent".

But he fell short of saying sorry. "In a democracy, everything is not perfect... mistakes are made," he said.

Apologies were offered by his national security adviser Condoleeza Rice, and Brig Gen Mark Kimmit.

"My army's been embarrassed by this," he said. "My army's been shamed by this.  And on behalf of my army, I apologise for what those soldiers did to your citizens."

It has also been confirmed that more than 2,000 Royal Marines will soon be on their way to the Iraqi town of Najaf and other positions in the centre of the country.

In a big expansion of Britain’s role in Iraq, Royal Marines from 3 Commando Brigade and also The Black Watch Regiment have been put on short-notice standby for Iraq.

They are expected to fly out early next month.