LONDON — The recriminations began long before the victory of Sadiq Khan had been announced.

As the votes trickled in Friday it soon emerged that Labour’s candidate was not only on course to win — but that he was going to crush his Conservative opponent Zac Goldsmith.

By early Saturday, Khan has ended the eight-year Convervatives' hold on London by a 13,6 percent of margin of victory over Goldsmith.

The Tory Party’s controversial “dog whistle” campaign, linking Khan with Islamist extremists, had backfired spectacularly, driving up Labour’s vote in the capital even in die-hard Conservative areas. After a slump in 2012, turnout for the election hit a surprise 44 percent for the mayoral vote Thursday.

Some commentators said the Tory campaign had simply failed to understand 21st London — a city younger, richer and far more diverse than anywhere else in the country. Almost to illustrate the point, it emerged late Friday afternoon that more people had voted for the “Cannabis is safer than alcohol” ticket than the far-right British National Party.

“London is an increasingly separate place,” one Tory minister told POLITICO as the result became clear. “It’s an example of the fragmentation of politics in the U.K. The politics in London are just so different to anywhere else I know.”

But there was also mounting concern that the party’s ferocious campaign could damage the Tory image elsewhere in the country. “This sort of thing doesn’t help. People could be left with the impression that when we’re talking about BME [black or minority ethnic] communities we’re only talking about extremism. We cannot afford to look like we are taking sides when it comes to race,” said the minister.

Others put it more brutally. One Conservative aide told reporters at London’s City Hall that the Tory campaign failed in London because it blew “a dog whistle in a city where there’s no dog.” London, it seems, just did not care about Khan’s Islamic faith. It may have even been a bonus.

A host of Conservatives took to the airwaves to attack the Goldsmith campaign as it became obvious that their candidate had lost.

The outgoing Conservative deputy mayor Roger Evans said attempts to link Khan to extremists had been “foolish” and would need “quite a lot of work” to repair. He told BuzzFeed: “I’m concerned that the campaign we’ve run is going to leave a negative legacy which we in London are going to have to clear up long after the people who ran Zac Goldsmith’s campaign have gone on their way.”

On the BBC, Mark Field, the Tory MP for the Cities of London and Westminster, added: “I prefer to play the ball rather than the man. In many ways with Zac it felt slightly ill at ease to be putting the boot in.”

Even Conservative commentators were furious. Daily Mail columnist Peter Oborne gave “three cheers for Sadiq Khan, the first Muslim London mayor.” He added: “Well done us Londoners, who voted for decency.”

The Spectator — the weekly magazine known as the Tory bible — said Goldsmith’s campaign “must be classed an embarrassment, and in some ways a disgrace”.

Landslide victory

With the result expected to be confirmed Friday evening, pollsters were projecting a 16-point victory for Khan over Goldsmith. Elections expert John Curtice said the Labour candidate was on course for a landslide victory once second preference votes were counted, with support from the left leaning Liberal Democrats and Greens likely to go to Khan.

The MP for Tooting, who was born and brought up in the U.K. capital by his Pakistani parents, was the heavy favorite going into Thursday’s vote, despite the Conservative campaign and a national scandal over allegations of anti-Semitism in the Labour Party.

Khan won 1, 310, 143 votes to Goldsmith’s 994, 614.

Khan replaces London's long-standing Conservative mayor Boris Johnson who has been in office since 2008. Johnson has returned to the House of Commons and is expected to stand for the leadership of the Conservative Party when David Cameron steps down.

Khan's win in the capital comes as a major relief for Jeremy Corbyn who suffered a series of traumatic losses in Scotland and lost overall control of the Welsh Assembly in Cardiff. Labour’s performance in England was more mixed, with the party losing seats overall but clinging on to a series of bellwether local authorities which many had expected them to lose.

A host of Labour figures criticized the nationwide performance — the first time an opposition has failed to make local election gains for over 30 years.

Chris Leslie, a former shadow chancellor, told the BBC: "We should have been absolutely wiping the floor with the Conservative Party. In some ways, we are falling backwards."

Tim Roache — general secretary of the GMB union, which is Labour’s third biggest donor — gave Corbyn a 12-month deadline to turn things around. He said the Labour leader had "a year or so" to show that he has what it takes to become prime minister in 2020. Roache said the party should have won "hundreds of seats" on English councils — not lost ground.

Corbyn congratutlated Khan on Twitter, saying "Can't wait to work with you to create a London that is fair for all." Khan nominated the veteran left-winger for the leadership last year, but did not vote for him and has attempted to distance himself from Corbyn throughout the campaign.

The Labour leader hailed Khan’s result in London already on Friday, lashing out at Conservatives. He said: "This vile campaign run by the Tories, the way they've tried to smear Sadiq Khan, the methods they've used and the language they've used, has had a very big effect in exactly the way they didn't want. So many people are just revolted by what was said about Sadiq yesterday they came out and voted for us.”

Corbyn’s battle now is to convince the public — and his MPs — that London voted Labour because of his leadership, not despite it.

This article has been updated to say Sadiq Khan was elected mayor of London.