SADIQ Khan said he hoped his election victory would inspire more Muslims to enter mainstream politics, despite the "desperate and divisive" campaign against him.

The new mayor of London, who was signed in to the office in a multi-faith ceremony at Southwark Cathedral, said he had been told of parents warning their children against a career in politics following the bitter campaign which saw the Tories try to link him to Islamic extremists.

Cabinet minister Michael Fallon said Zac Goldsmith's campaign, which has been criticised by senior Tories, was part of the "rough and tumble" of an election.

READ MORE: Warm welcome as Sadiq Khan is sworn in as Mayor of London

The Tooting MP became the first Muslim to take the top job in City Hall after securing 57% of the support once second preferences were taken into account.

Meanwhile, the lengthy counting process following the "Super Thursday" elections continued, with further results expected in Northern Ireland.

Around 100 of the region's 108 MLAs are now elected to serve in Stormont, with the Democratic Unionists and Sinn Fein on course to retain their positions as the major parties in the power-sharing coalition administration.

After the success in London, Labour will also hope for a victory in Bristol's mayoral contest, where Marvin Rees is aiming to oust independent George Ferguson.

A handful of English councils were also declaring results on Saturday.

The results in London and across England mean Labour leader Jeremy Corbyn has survived his first major electoral test, but critics - including within his shadow cabinet - continued to express doubts about him.

The Labour leader was notably absent from the ceremony which saw Mr Khan signed in as mayor, even though his predecessor Ed Miliband was present.

Mr Khan said his victory was down to a "positive" campaign which offered answers to some of the problems facing the capital.

He said: "I'm mayor of London now. I've got bigger things to worry about than Zac Goldsmith's campaign. It's for them to ask themselves the question, how is it that in the most diverse and fantastic city in the world they chose to have a negative, desperate and divisive campaign?"

He told Sky News: "I have spent my entire life fighting extremism and radicalisation, encouraging minority communities to get involved in mainstream politics and civic society, and I have managed to do that.

"But in the last few weeks I have had dozens and dozens and dozens of parents, uncles and aunties, grandparents, saying 'you know what, our son or daughter was thinking about going into politics, our nephew or niece was thinking about going into politics, but after seeing what has happened to you we are advising against that'.

"I'm hoping the result on Thursday encourages young people to get involved in mainstream politics, encourages Londoners of Islamic faith and other minority communities, encourages British Muslims and others to get involved in civic society and get involved in mainstream politics.

"The decency of Londoners, the decency of British people will always cut through."

He said it was a matter for David Cameron whether he wished to apologise for the conduct of the Tory campaign, but vowed to work with the Prime Minister in the interest of Londoners.

READ MORE: Tories defend Zac Goldsmith campaign as Sadiq Khan elected London Mayor

Mr Fallon described Mr Khan as a "Labour lackey who speaks alongside extremists" during the mayoral race, and was repeatedly challenged on the BBC Radio 4 Today programme to say whether he was worried about the capital's security with Mr Khan in City Hall.

"London is safe with a Conservative Government working with the new mayor of London," he said.

Tory former justice secretary Ken Clarke told the BBC the way the campaign had been run was a "mistake" and "probably had a counter-productive effect".

But Mr Fallon said: "Both candidates were asked questions about their backgrounds, their personalities, their judgment, the people they associate with. That's the nature of our democracy and the rough and tumble of politics."