The possibility of Jeremy Corbyn winning the Labour leadership terrifies the political establishment, partly because of his consistent anti-war record

A Labour leader who might actually support seeking justice over the illegal Iraq war? Only a few weeks ago such a thought would barely merit consideration.

The three original candidates have none of them distinguished themselves over foreign policy or of opposing foreign wars. But now, in an interview with BBC Newsnight’s Emily Maitles, frontrunner in the leadership campaign Jeremy Corbyn has made it clear that he would support such moves against Tony Blair and others involved in the prosecution of the Iraq war, if the evidence was there to suggest that they had committed war crimes.

I would expect nothing less from a principled and honest MP who has always opposed wars and who spoke at the first mass meeting of Stop the War when it was founded back in 2001.

He was part of the major Labour revolt against Blair in March 2003 when he voted against the imminent war,  but when Blair was able to carry the vote with the overwhelming backing of the Tories (a point that should never be forgotten).

Jeremy Corbyn also demonstrated at the various stages of the infamous Chilcot inquiry, and before that those of Hutton and Butler as well. He is chair of the Stop the War Coalition.

Jeremy was careful to stress that there has to be evidence of such war crimes, but he also made it clear that he already thought there was ample evidence that the war in Iraq was illegal under international law, a view he said he shared with former UN secretary general Kofi Annan.

His view is, however,  breath of fresh air among politicians who ignored public opinion expressed through the biggest British demonstration ever in 2003, who cynically believed that the drive to war would soon be forgotten, and who have been complicit in refusing an open and honest accounting of the war.

The official government inquiries into the war have been a sick joke, presided over by safe pairs of hands in the form of the great and good of the establishment. The Lords and knights who have judged these inquiries have been shown to have more concern for the sensitivities of those who justified the war than any concern to find the real truth. Chilcot stopped taking evidence over 4 years ago, but still his rumoured report is nowhere in sight.

We should not underestimate the shock waves on this issue if Jeremy Corbyn becomes leader. He will end the cross party consensus which is only rarely broken -as it was by Ed Miliband when he voted against bombing Syria two years ago, a position which he failed to maintain in 2014 over Iraq.

A leader who raises the disaster that was Iraq alongside all the other disasters of the war on terror will be breaking with the past 14 years and will provide a huge problem for Cameron’s warmongering.

Already the prime minister’s plan of an immediate vote on bombing Isis in Syria following the leadership election may have to be put on hold, because Cameron relies heavily on cross party consensus.

More importantly, Jeremy’s candidacy begins to redress the terrible crime on the people of the Middle East and of Britain which was the Iraq war.

It is impossible to know how many people now supporting him were among those who left Labour in 2003 or who vowed they would never vote Labour again following the war, but there must be a reasonable number. Labour lost 1 million votes in 2005, usually assumed to be because of the war. Many of those not voting in the last general election will be anti war.

The war and foreign policy remain central to political ideas in Britain, despite the attempts by politicians and media to relegate them to side issues. Jeremy Corbyn’s candidacy puts them back at centre stage.