Sadiq Khan becomes London's first elected Muslim mayor.

LONDON — Labour candidate Sadiq Khan has been elected Mayor of London, beating his Conservative opponent Zac Goldsmith.  

Khan, 45, replaces flamboyant Conservative Boris Johnson after a race characterised by allegations of extremism and racism. 

Goldsmith called Khan — who is Muslim — a "radical" and accused him of giving "platforms, oxygen and even cover" to Islamic extremists. 

His allegations were echoed by prime minister David Cameron in the parliament, during Wednesdays' question time. 

The son of a bus driver from Pakistan, Khan is a former human rights lawyer who branded himself "the British Muslim who takes the fight to the extremists." 

Before the elections, he promised to be "a mayor for all Londoners," urging voters to "choose hope over fear." 

A difficult campaign

Tony Travers, a local government expert at the London School of Economics, said the introduction of a directly elected London mayor 16 years ago had introduced "an American form of government" that differs from traditional British parliamentary and local government structures.

"Now intriguingly this time — and we've seen a bit of it before — it appears to have brought with it some of the harder American campaign tactics," he said ahead of the result.

A victory for Khan is a bright spot in what looks set to be a grim day for Labour, which has been out of office nationally since 2010.

Opposition parties usually gain seats in midterm elections as voters punish the sitting government. But Labour under left-wing leader Jeremy Corbyn is divided and beset by a controversy over allegations of anti-Semitism within its ranks. The claims gained new momentum when former London Mayor Ken Livingstone — a Corbyn ally — claimed that Adolf Hitler had supported Zionism before he came to power.

Livingstone, Labour lawmaker Naz Shah and several local party officials have been suspended over comments or social media posts about Israel, and Corbyn has faced renewed pressure over his links to pro-Palestinian groups.

About 2,700 local council seats are up for grabs, and Corbyn predicted last week that Labour wouldn't lose ground — but later said that "predictions are not that important."

A poor showing would bolster discontented Labour lawmakers who believe the party is heading for a third straight general election defeat in 2020 if Corbyn — a life-long socialist with strong support among the party's grass roots — is not replaced.