Labour leader Jeremy Corbyn has said he is likely to back a House of Commons motion accusing his predecessor Tony Blair of misleading parliament over the Iraq war.
A number of senior MPs plan to table a motion this week to find Blair in contempt of parliament over the 2003 invasion, following Sir John Chilcot's damning report last week.
The MPs, including Tory David Davis, the SNP's Alex Salmond and the Green Party's Caroline Lucas, believe Blair deceived MPs and led Britain into war under false pretences.
If the contempt motion is accepted, it could be debated and voted on later this month. Lucas claimed it could result in Blair being "barred from public office".
Meanwhile Lord John Prescott, who was deputy prime minister at the time of the invasion, said on Sunday that he now believed the war was illegal and apologised to the nation.
Davis told BBC1's Andrew Marr Show the motion would state "that Tony Blair has held the House in contempt".
He added: "It's a bit like contempt of court. Essentially by deceit ... If you look just at the debate alone, on five different grounds the House was misled – three in terms of the weapons of mass destruction, one in terms of how the UN votes were going, and one in terms of the threat, the risks.
"He [Blair] might have done one of those accidentally, but five?"
Corbyn, who long campaigned against the Iraq war, said the Chilcot report had highlighted how parliament was "denied the information it should have had" and pointed to the government's "assertions of weapons of mass destruction".
"Parliament must hold to account, including Tony Blair, those who took us into this particular war," he told the Marr show.
Asked whether he would back the contempt motion, Corbyn said: "I haven't seen it yet, but I think I probably would."
The motion is expected to be tabled after MPs hold a two-day debate on the Chilcot report on Wednesday and Thursday.
In a statement, Lucas said: "The Chilcot report is a damning indictment of Blair’s record. It showed that the former prime minster actively deceived parliament and led this country into a disastrous and bloody war under false pretenses.
"I’m joining with fellow MPs to hold Blair to account by tabling a contempt motion which could see him barred from public office and have his privy counsellorship stripped from him."
The families of UK soldiers killed in the Iraq war are already considering legal action against Blair. Sarah O'Connor, whose brother Sergeant Bob O’Connor was killed in 2005, said: "There’s one terrorist in this world that the world needs to be aware of – and his name’s Tony Blair."
Writing in the Sunday Mirror, Prescott said: "I will live with the decision of going to war and its catastrophic consequences for the rest of my life.
"In 2004, the UN secretary-general Kofi Annan said that as regime change was the prime aim of the Iraq war, it was illegal. With great sadness and anger, I now believe him to be right."
A spokesperson for Blair declined to comment on the motion. But Margaret Beckett, a cabinet minister under Blair, spoke out against it.
She said in a statement: "The Chilcot report was never going to settle the arguments about the war. The people behind this contempt motion were always going to use the Chilcot report for their own ends.
"It is, however, very clear from the Chilcot report that Tony Blair did not lie, did not falsify intelligence and that the cabinet was not misled on the presentation of the legal advice.
"As a member of the cabinet at the time, I am clear that the attorney general provided a clear legal basis for military action which was consistent with all the information with which cabinet had been presented on a regular basis over the previous weeks."