Jeremy Corbyn has backed a parliamentary motion declaring Tony Blair guilty of “contempt”, following the release of the Chilcot Report.

The motion, set to be tabled by outspoken Conservative MP David Davis, alleges that the former prime minister deceived the House of Commons while making the case for Iraq.

The Labour leader, who this week apogised on behalf of his party for the war despite being having long personally opposed it, said he would “probably” back the motion when asked.

“I urge colleagues to read the Butler Report and the Chilcot Report about the way Parliament was denied the information it should have had, the way there was lack of preparations for the conflict’s aftermath, and the way in which assertions of weapons of mass destruction [were made],” he told BBC One’s Andrew Marr Show.

“Parliament must hold to account, including Tony Blair, those who took us into this particular war. That is surely how a parliamentary democracy works. I haven’t seen [the motion] yet, but I think I probably would [back it].”

The motion is likely to debated in the next few weeks if it is accepted by the Speaker.

The landmark Chilcot Inquiry, which has been investigating the 2003 invasion since 2009, said last week that Mr Blair’s intelligence case for the attack on Iraq was “not justified”.

Mr Corbyn’s backing comes after John Prescott, the deputy prime minister at the time of the invasion, said Mr Blair had led Parliament into backing an illegal war.

Sir John Chilcot found Tony Blair presented the case for war with 'a certainty which was not justified' (Getty Images)

Writing in the Sunday Mirror newspaper, Lord Prescott said that following evidence in the Chilcot Report he had come to the conclusion that the war was illegal.

“I will live with the decision of going to war and its catastrophic consequences for the rest of my life,” he wrote.

The key players in the Iraq War Show all 11 1 /11 The key players in the Iraq War The key players in the Iraq War Jack Straw Jack Straw was the UK foreign secretary at the time of the Iraq invasion, and fully endorsed the decision Getty The key players in the Iraq War Geoff Hoon Geoff Hoon was Tony Blair’s defence secretary from October 1999 to May 2005 Getty Images The key players in the Iraq War Alastair Campbell Alastair Campbell was involved in the drafting of two Downing Street dossiers on the war, in September 2002 and in February 2003 Getty The key players in the Iraq War John Scarlett John Scarlett was chairman of the Joint Intelligence Committee at the time of the 2003 invasion Getty Images The key players in the Iraq War Peter Goldsmith Peter Goldsmith was Mr Blair’s attorney general from 2001 to 2007 AFP/Getty Images The key players in the Iraq War Condoleezza Rice Condoleezza Rice was named as National Security Advisor to George W Bush in 2000, becoming the first woman to occupy the post, and argued publicly in favour of the 2003 invasion Getty Images The key players in the Iraq War Colin Powell Colin Powell was Secretary of State from 2001 to 2005 Getty Images for TIME The key players in the Iraq War Tommy Franks Tommy Franks was the leading US general at the start of the Iraq war The key players in the Iraq War Dick Cheney Dick Cheney was George W Bush’s vice president from 2001 to 2009 Getty Images The key players in the Iraq War Paul Bremer Paul Bremer ran Iraq for 14 months after the invasion, appointed Bush’s Presidential Envoy in charge of the occupying forces Getty Images The key players in the Iraq War Hans Blix Hans Blix was the UN weapons inspector tasked with monitoring Iraq from 2002 to 2003 Getty Images

“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.”

Mr Davis, who is tabling the motion, also told the Andrew Marr Show: “I'm going to put down a contempt motion, a motion which says that Tony Blair has held the House in contempt. It's a bit like contempt of court. Essentially by deceit.”

He added: “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 the UN votes were going, and one in terms of the threat, the risks. He might have done one of those accidentally, but five?”

Overall Sir John Chilcot, who chaired the Iraq Inquiry, was damning in his verdict on the invasion.

“We have concluded that the UK chose to join the invasion of Iraq before the peaceful options of disarmament had been exhausted. Military action at that time was not a last resort,” he said on Wednesday.

“We have also concluded that the judgements about the severity of the threat posed by Iraq’s WMD were presented with a certainty that was not justified.