The London mayor has called on MPs from all parties to set aside their political careers and consider supporting soft Brexit Lords amendments as they return to the Commons in votes that he said were as significant as those that took Britain into the Iraq war.



Sadiq Khan in effect added his voice to those calling on Jeremy Corbyn to oppose Britain’s departure from the single market as he said MPs should “be brave” and support EU withdrawal bill amendments in the coming weeks.

The key piece of legislation was expected to return to parliament within the next fortnight, after being amended 15 times by peers. Fourteen of those amendments were backed by the Labour frontbench but Corbyn is unlikely to support the 15th, a bid to keep Britain in the European Economic Area.

The government is most likely to face defeat over the issue of remaining in a customs union, where Labour will hope to win the backing of as many Conservative rebels as possible.

Khan told the Guardian it was “extremely rare that parliament faces a vote that is more important than party politics, more important than MPs’ ministerial careers and which will define that generation of parliamentarians in the history books”.

Invoking the memory of Labour MPs such as Robin Cook, as well as Corbyn, who voted against the 2003 Iraq war, Khan added: “The last vote of this significance was the vote on the Iraq war – when there were brave MPs from all parties who did the right thing and voted against the war regardless of the consequences.” Khan himself was not in the Commons at the time, having only become an MP in 2005.

“Parliament has the opportunity to reject the Tories’ shambolic and reckless handling of Brexit and preserve our prosperity for the next generation – if MPs are brave,” the mayor added.

Peers inflicted a string of often heavy defeats on legislation that had cleared the Commons, including on an amendment that called on ministers to outline the steps taken to negotiate the UK’s participation in a customs union before leaving the EU and another that called on the government to set remaining in the EEA as a negotiating objective.

In common with many Labour backbenchers, Khan has previously argued that the UK should remain in the customs union and the single market, as he seeks to reflect the views of a city where 59.9% of people voted remain.

But his remarks also came at a time when he faces the prospect of being challenged by Justine Greening, a Conservative MP and former minister who supported remain but has since voted in favour of the government’s version of the EU withdrawal bill.

Greening has emerged as an early frontrunner for the Conservative mayoral nomination after one talked-about candidate, Ed Vaizey, a former culture minister, said on Friday he would not run and endorsed the MP for Putney instead.

Party nominations open this month and a candidate due to be selected by members in September, and although Greening has not said she will run, her name has emerged as a plausible contender. Another former minister whose name has been mentioned, although more speculatively, was George Osborne, but senior London Conservatives question if his hostility to Theresa May would discourage party members from voting for his nomination.



Khan called on Conservative and Labour MPs to signal that they are prepared to defy their whips if necessary over Brexit. “My message to my former colleagues in parliament is: don’t think about the headlines, your career or the campaign groups when deciding how to vote – think about your constituents and vote for what you think is in their best interest.”