David Cameron hailed the "extraordinary coalition" rallied behind Britain remaining in the European Union as he campaigned alongside Labour's Sadiq Khan.

The Prime Minister shook hands with the London Mayor and hailed the election of the "proud Muslim and proud Brit" just weeks after being accused of racist slurs against him.

They joined forces to launch a five-point "guarantee" card and a campaign battle bus as the PM sought to refocus attention away from increasingly public Tory dissent against his leadership.

In a clear effort to steer public attention from the bitter battles dividing his own party, he said his appearance with Mr Khan was symbolic of the wider agreement across the political spectrum.

"It has brought together this extraordinary coalition - Labour, Liberal, Conservative, Green, business, trade union, NGO - all together knowing this is the right answer."

He laughed off suggestions by pro-Brexit campaigners that widespread warnings of an economic shock if Britain votes to leave were "part of some massive establishment conspiracy".

"It would be a pretty exquisite conspiracy that could bring together the Labour mayor son of a bus driver and the Tory son of a stockbroker Prime Minister.

"Sadiq and I say it for this reason: because we love our country, we want our country to be the best we possibly can, to be the strongest, to be the greatest.,

"For our economy to be strong, for families finances to be secure, to go on creating jobs. This is not, in the end, an argument about Europe. It is an argument about Britain."

He acknowledged there was "uncertainty and confusion" amid claims of scaremongering by both sides and pledged "to speak clearly, to speak positively" for the rest of the campaign.

Mr Khan - appearing alongside the PM in front of students in south-west London - said he would work closely with the Tory government "where it is in Londoners' interests".

The economic case for staying in was "crystal clear", he said, "but there is a patriotic case as well".

"This vote is about our values, it is about our character, it is about how we see our city and our country in the future.

"The reason why London is the greatest city in the world - and it is - we have never taken an isolationist approach, we are open-minded, we are outward-looking, we embrace other cultures and learn from other cultures and ideas as well."

Mr Cameron said: "We will disagree about many things. We have in the past; I'm sure we will again in the future.

"But we are both on the side of London, we are both on the side of the United Kingdom. I want that spirit of unity of purpose to be with us today."

The PM spoke about each of the five "guarantees" being offered by the Remain campaign: full access to the EU's single market; workers' rights protected; keeping the European Arrest Warrant (EAW); a special status in Europe; and stability for our country.

He has been accused of spearheading a negative campaign reliant on economic warnings.

He said he saw himself as a "Eurosceptic" - highlighting his efforts to seek change in Brussels - but said identifying weaknesses in the EU was a "sign of strength" of the in campaign.

"Because we are levelling with people which is something the other side refuses to do," he said - seizing on the admission of Ukip's Diane James that rivals "just don't know" whether Britons would need visas to travel to Europe post-Brexit.

"'We just don't know' is not good enough for the British people," he said.

Defending the EAW, he said it had ensured one of the 21/7 terrorists had been returned from Italy to face justice in the UK quickly rather than after "years or decades".

"Who wants to give that up when we think of voting on June 23?"

Mr Khan refused to criticise Jeremy Corbyn's decision not to campaign alongside the Prime Minister, saying he is already contributing a "huge amount" in other ways.

The Labour leader has previously said it "would not work" for him and Mr Cameron to make the case for remaining in Europe side by side.

Mr Khan said: "I'm here speaking as the Mayor of London and campaigning with the British Prime Minister to persuade as many Londoners as I can - and those around the country - why a vote to Remain is so important for us as a country.

He added: "Jeremy Corbyn is doing a huge amount of campaigning to persuade people around the country about why it is in our interest to remain in the European Union, and I'm sure he will carry on doing that until 10pm on June 23."

Ukip MP Douglas Carswell, speaking for Vote Leave, said: "David Cameron cannot be trusted.

"Just a month ago he attacked Sadiq Khan as a terrorist sympathiser yet today he hailed him as a great politician as he stood next to him on a shared platform," the former Tory said.

"Today he trumpeted the benefits of the European Arrest Warrant but a few years ago he warned that it was dangerous and that it stripped away centuries-old rights from the British people."

Vote Leave said Mr Cameron had criticised the EAW in an article 15 years ago and dismissed each of the in campaign's "guarantees".

Boris Johnson refused to be drawn on the comments by Tory grandee Ken Clarke that he was a "nicer version of Donald Trump".

Speaking at an event with Sir Ian Botham in Chester-le-Street, County Durham, he said: "I think it's very important with such a short time to go that we all focus on the issues that matter to the people of this country.

"What the public want to hear is how we are going to take back control of £350m a week that gets taken off and we don't control any more."

At the town's cricket club, a few decent slogs up the road from the Riverside ground where England had just won against Sri Lanka, Mr Johnson played a straight bat when asked about Mr Cameron and Mr Khan sharing a platform.

"I'm not here to talk about personalities, and alliances and who talks to whom," he said. "My job in the next 23 days, whatever we have got left, is to get over our key messages.

"This is the only chance in our lifetimes to go for a new approach, a democratic approach, but still leading in Europe."