Chilcot, the damning dossier that means Blair will never wash out the stain of the Iraq War
When you ask Labour MPs how the party travelled from Tony Blair to Jeremy Corbyn in just eight years, many reply with just one word: "Iraq". The view runs through the party, from ardent Blairites to ultra-loyal Corbynistas.
The Iraq War has cast a long shadow over Labour. It prevented Blair securing a bigger majority than the 66-seat one he won in 2005, down from 167 at the previous election. That deprived Gordon Brown of a bigger cushion that might have saved him when he fought his only general election as prime minister in 2010, and lost.
The explosion over Iraq among Labour members was delayed, but always bound to happen. Behind the scenes, Ed Miliband devoted enormous amounts of energy to keeping the party united. But when he stood down as leader last year, the fuse was lit. Members who had quit, many over Iraq, returned to vote for Corbyn in the leadership election. Many of those who had remained seized their chance to bury New Labour. Although there were other concerns - such as being Tory-lite on the economy - Iraq was a symbol of everything they disliked. The result: a derisory 4.5pc of the vote for the Blairite Liz Kendall, and an incredible 59.5pc for Corbyn, then chair of the Stop the War Coalition and a campaigner against the 2003 invasion of Iraq.