David Cameron and Sadiq Khan join forces on Brexit

British Prime Minister David Cameron and new London mayor Sadiq Khan appeared to have put aside their animosity over the long weekend by campaigning together for Britain to remain in the European Union.

It comes after Cameron said Khan, a member of the opposition Labour Party, had shared a platform with people with extremist views during the mayoral election campaign.

Cameron eventually apologized to a Muslim cleric he had accused of supporting the Islamic State extremist group and linked to Khan. The cleric, Suliman Gani, said he was “totally opposed” to the terror group.

Khan, the son of a bus driver from Pakistan, was elected London’s first Muslim mayor in early May. He accused Cameron’s Conservative Party of running a “nasty, dog-whistling campaign.”

Speaking at the launch of a campaign bus and pledge card in London on Monday for the Britain Stronger In Europe campaign group, Cameron congratulated Khan on his victory.

“In one generation someone who’s a proud Muslim, a proud Brit and a proud Londoner can become mayor of the greatest city on Earth. That says something about our country,” Cameron said.

“There are still glass ceilings we have got to smash. There’s still discrimination we have got to fight. I’m proud to be here with the mayor of London — with the Labour mayor of London — on this vital issue.”

“There are many things upon which the prime minister and I will disagree,” Khan said at the event.

“But what’s really important is when it’s in London’s interests for the mayor of London and the government to work closely together, we will work closely together.”

The referendum on whether Britain should remain in the EU will take place on June 23.