Election of first Muslim mayor of major western capital promises to offset big losses in Scotland as SNP maintains grip on Holyrood

Sadiq Khan’s election as London mayor in the early hours of Saturday handed a boost to Labour leader Jeremy Corbyn at the end of a difficult day in which Labour held ground in England but endured a disastrous defeat in its former heartland of Scotland.

Khan’s landslide victory over his rival, Conservative Zac Goldsmith, in which he secured more than 1.3m votes made him the first Muslim mayor of a major western capital, and gave Labour the keys to City Hall after eight years of Conservative control, following a bitterly fought and controversial campaign.

As the votes were being counted, senior Tories and even Goldsmith’s own sister criticised his team’s strategy, which included repeated claims from the candidate himself and David Cameron that Khan had shown bad judgment by sharing platforms with alleged extremists.

The former Conservative party chairman Sayeeda Warsi attacked the Goldsmith campaign on Twitter, claiming: “Our appalling dog whistle campaign for #LondonMayor2016 lost us the election, our reputation & credibility on issues of race and religion.”

Steve Hilton, Cameron’s former director of strategy who was part of an effort to “detoxify” the Tories, told BBC Newsnight that Goldsmith had brought back the “nasty party label to the Conservative party”.

Speaking after finally being declared winner after midnight, Khan said that he grew up on a council estate and “never dreamt that someone like me could be elected as mayor of London”.