The Sunday Times and the Sunday Express both carried reports that Scottish and Welsh nationalists will put forward an amendment to the Queen's Speech on Wednesday, calling for a government statement on any pull-out.
Blair's government has come under renewed scrutiny for Britain's support of the US-led invasion of Iraq and narrowly scraped through a recent vote calling for a parliamentary inquiry into its involvement and the aftermath.
The Sunday Express said Scottish National Party (SNP) and Plaid Cymru members of parliament will use an obscure parliamentary procedure last used in 1923 to force the government's hand.
Then, the Liberal party successfully deployed the tactic to force a debate about Britain's three-year occupation of newly-created Iraq under a League of Nations mandate -- the forerunner to the UN -- following World War I, it added.
Plaid Cymru MP Adam Price -- who led an unsuccessful campaign for Blair to be impeached over Iraq -- was quoted as saying that it was "unacceptable" to have a debate on Iraq in the United States and not one in Britain.
Price said the situation had changed because of the Democrats' rout of the Republicans in the US mid-term elections last week -- where Iraq was a factor -- and the current proceedings of the bipartisan Iraq Study Group.
Blair is due to give evidence to the panel led by former US secretary of state James Baker via videolink on Tuesday.
The Welsh MP said that government whips would "find it very difficult to vote down this amendment, which is doing nothing more than asking the government to set out its strategy so we can have a full debate on it".
The House of Commons speaker traditionally has to select two amendments to the Queen's Speech, in which the monarch sets out her government's planned legislation for the coming year.
The official opposition -- the Conservative Party -- will have one amendment selected but the second can come from any opposition party, including the Welsh and Scottish nationalists.

Copyright AFP (Agence France-Presse), 2006
`