Tony Blair, who narrowly defeated a recent parliamentary attempt to call an inquiry into the Iraq war, is facing a new threat from Washington, where victorious Democrats are expected to call British witnesses as they launch congressional investigations into the war.
"Now we are the majority party and we can hold hearings," said a senior member of the staff of John Conyers, who in January will become chair of the House Judiciary Committee. "We can hold any number of hearings."
Democratic Senators are also expected to seek hearings aimed at throwing light on how Downing Street and the White House co-ordinated efforts to claim that Saddam Hussein possessed weapons of mass destruction. All the claims that led to war, from allegations that Saddam was reconstituting a nuclear weapons programme to his alleged links with al-Qa'ida, could come under examination. Unlike their counterparts in Britain, congressional committees have the crucial power to subpoena witnesses and documents.
Mr Conyers's staff have long been investigating how false information was presented by the Bush administration to persuade the public of the "significant and growing" threat posed by Saddam. Their inquiries were partly triggered by the leaking of the Downing Street memos, which revealed the belief of the British government that Mr Bush had decided on war as early as the spring of 2002.
When Mr Conyers published his findings last year, he said: "We have found that there is substantial evidence the President, the Vice-President and other high-ranking members of the Bush administration misled Congress and the American people regarding the decision to go to war in Iraq, misstated and manipulated intelligence information regarding the justification for such war, countenanced torture and cruel, inhuman and degrading treatment in Iraq, and permitted inappropriate retaliation against critics of their administration."
He called for Mr Bush's censure, something that Democrats have now decided not to pursue, but any fresh investigation using subpoena powers is sure to put further pressure on the US and British governments.
Three and a half years into a conflict that has led to the deaths of more than 2,800 US troops, 121 British soldiers and perhaps 655,000 Iraqis, the Congressman's aide said full details about the decision to go to war had still not emerged. He added: "We are not in a position to say we know what happened or what came to be. We know what some whistle-blowers said, and some people who left the government, but there has never been a [full inquiry]."
Pressure for an inquiry in the UK will be renewed this week when MPs launch a fresh attempt to make the Government reveal its exit plan from Iraq. Leading backbenchers from all sides are preparing to table an amendment to the Queen's speech, a device that, if successful, would require ministers to explain in public what they are telling the US administration in private.
Kenneth Clarke, the former chancellor and leading Conservative war critic, and John McDonnell, the left-wing Labour MP challenging for the party's leadership, are among those backing the move.
And the foreign affairs committee is waiting to receive secret evidence about the run-up to war from Carne Ross, a former British diplomat. In an extraordinary session of the committee last week, Mr Ross, a close friend of Dr David Kelly, offered to make public evidence he gave in secret to the Butler inquiry.
The offer threatens to develop into a major embarrassment for the Government, since the FAC's Labour chairman, Mike Gapes, a Blair loyalist, urged him not to disclose his evidence.
Among those who gave evidence to Mr Conyers last year was Joe Wilson, a former US diplomat who proved Mr Bush was wrong to claim Iraq had tried to obtain uranium in Africa. The administration later admitted that the claim, which the President attributed to Britain, should never have been in his 2003 State of the Union address.
Mr Wilson said he was willing to testify, adding that he had been following the claims by Mr Ross in London. "The whole question of pre-war intelligence has not been resolved," he said.
Downing Street confirmed Mr Blair will give evidence by video-link on Tuesday to the Iraq Study Group, a high-level Washington commission, chaired by former US secretary of state James Baker, which is trying to devise a new course for the war.
Mr Blair is expected to urge the US to push for a solution to the Israeli-Palestinian conflict to defuse Middle East tensions. Britain also favours talks with Iraq's neighbours, Syria and Iran. Although little help is expected from Tehran, British ministers are also understood to be discussing suggestions that Syria might help to quell violence in Iraq in exchange for regaining the Golan Heights, seized by Israel in 1967.Reuse content