Tony Blair faces a fresh move by senior MPs to set up a full Parliamentary inquiry into the UK role in the run up to the Iraq war and its aftermath.
Tory Ken Clarke and Lib Dem deputy leader Sir Menzies Campbell are among those backing the cross-party motion.
They are aiming to get 200 signatures and get a debate in the Commons.
Another signatory, SNP leader Alex Salmond, said: “This apparently modest motion may be the iceberg towards which Blair’s Titanic is sailing.”
There have been four separate inquiries into different aspects of the Iraq war, including the Butler report into intelligence failings and the Hutton inquiry.
But there has yet to be an an inquiry focusing on the way the government’s decision to join a US-led invasion was made.
The MPs’ motion calls for the setting-up of a special select committee to carry out this task.
The seven strong committee would be members of the Privy Council and therefore able to look at sensitive intelligence material.
The other signatories so far are Douglas Hogg, a former Tory cabinet minister, Elfyn Llwyd, the Plaid Cymru leader, and Alan Simpson, Labour MP for Nottingham South, a prominent left-winger.
The motion is headed: “Conduct of Government policy in relation to the war against Iraq.”
It reads: “This House believes there should be a select committee of seven Members, being Members of Her Majesty’s Privy Council, to review the way in which the responsibilities of government were discharged in relation to Iraq and all matters relevant thereto in the period leading up to military action in that country in March, 2003 and in its aftermath.”