Sadiq Khan, Britain's Labor Party candidate for Mayor of London and his wife Saadiya pose for photographers after casting their votes for the London mayoral elections at a polling station in south London, Britain, May 5, 2016. [Photo/Agencies]

Accusations

Khan held his lead in the opinion polls, despite accusations by Goldsmith that he has shared platforms with radical Muslim speakers and given "oxygen" to extremists.

Khan says he has fought extremism all his life and that he regrets sharing a stage with speakers who held "abhorrent" views. The Labor Party accused Goldsmith and the ruling Conservative Party of smearing Khan.

Goldsmith denied the charge, saying he had raised legitimate questions over his opponent's judgment - but the tactics do seem to have backfired with some voters interviewed by Reuters saying they found the campaign "disgusting and slimy".

Sadiq Khan, Britain's Labor Party candidate for Mayor of London, poses for a selfie with supporters at Canary Wharf in London, Britain, May 4, 2016. [Photo/Agencies]

While fighting those charges, Khan, a former human rights lawyer, also distanced himself from the newly elected Labor leader, Jeremy Corbyn, after a row over anti-Semitism.

The Labor leader ordered an inquiry into charges of anti-Semitism after suspending Ken Livingstone, a political ally and a former London mayor, for saying Adolf Hitler had supported Zionism.

The impact of the crisis was difficult to gauge in the election of more than 2,700 local officials and new devolved authorities in Scotland and Wales.

Compared to the last regional elections in 2011, Labor's share of the vote was down 9.2 percent in Scotland and 7.6 percent in Wales, allowing a strong showing for the anti-EU UK Independence Party before a referendum on membership of the bloc on June 23.

But, with fewer losses in England than expected, Corbyn was able to rally enough support to prevent an early challenge.

Corbyn, who was elected as party leader last year on a wave of enthusiasm for change and an end to 'establishment politics' among mostly younger members, welcomed some of the results and said he would fight to re-establish Labor in Scotland.

"We hung on and we grew support in a lot of places," he said.