By Bridget Kendall
BBC diplomatic correspondent
What better day for Britain's foreign and defence secretaries to face a joint grilling from the parliamentarians who sit on the foreign affairs and defence select committees?
The US is planning to raise troop numbers by 20,000
It was an unusual event, and one which revealed just how much concern there is in the Commons about where Iraq might be heading and what that could mean for Britain and its military force in southern Iraq.
The MPs asked a series of pointed questions.
They tried to get the ministers to open up about the British government's view of President Bush's new plan.
They wanted to know if Britain backed it wholeheartedly and thought it could work.
They were worried about any possible backlash that could affect British security responsibilities around Basra and elsewhere in the south.
Hard to decipher
They tried to pin down exactly what the British government thought about President Bush's tough stand against Iran and Syria, and his refusal to draw them into new regional diplomacy on Iraq.
But while the questions showed a widespread scepticism across the board in the Commons about any new "surge" in Iraq, the answers were not always so easy to decipher.
Mrs Beckett denied any rift with the US on Iraq policy
Yes, President Bush did use strong language about Iran and Syria, agreed the foreign secretary, Margaret Beckett.
But, she argued, he was quite rightly talking about their negative interference in Iraq.
Destroying the networks that were providing weapons across the border was what British troops were also trying to do (apparently with some success, though military details were only promised to the MPs in private).
And, she added, the Americans were still holding out the offer of direct talks to Iran, under certain conditions.
Her argument was an attempt to suggest that "constructive engagement" with Iran had not been entirely ruled out by Mr Bush.
But most of the MPs thought his warning that he would "seek and destroy" those who interfered with Iraq could not square with the growing chorus of calls urging the US government to invite all Iraq's neighbours to join the search for a solution.
Worries that going after Shia militias in Baghdad might have an impact on security in Basra and the rest of southern Iraq were dealt with by Defence Secretary Des Browne.
He was not reassuring.
He admitted it was a possibility that if you disturbed the Shia in Sadr city in Baghdad, the Shia in Basra might rise up. Indeed, it had happened in the past.
"We continually reassess the risk," Mr Browne said.
As for whether the plan would work and who would take responsibility if it failed, that provoked a heated exchange.
Surely, said some MPs, President Bush's insistence this was also partly an Iraqi plan was an attempt to pass the buck ahead of time and shift the blame if it went wrong?
Mrs Beckett heatedly denied this.
"The Iraqis want to have the transfer of responsibility," she said, "They are pushing for faster and greater transfer of responsibility to themselves.
"It is not something that is being driven or forced on them by us or anybody else."
And so does the British government think it will work?
Mr Browne pointed out lessons had been learnt from previous mistakes.
Just clearing areas of militants was not enough. This time areas had to be held.
Unlike the last time, there had been an attempt to secure the city and the Iraqi government had promised troops would have access to all parts of Baghdad, in theory leaving gunmen no havens to hide.
But in answer to a blunt question - would the future of Iraq be won or lost in the suburbs of Baghdad? - the two ministers hardly gave their wholehearted support.
Baghdad was more challenging than Basra, agreed Mr Browne.
There had been a reassessment that acknowledged flaws, difficulties and obstacles, said Mrs Beckett.
The new plan was intended to overcome past obstacles.
But if no headway could be made in Baghdad, she warned, then the situation would be very serious indeed.