David Cameron and Sadiq Khan just formed an unlikely alliance

David Cameron and London's Labour Mayor, Sadiq Khan, have teamed up to campaign to keep Britain in the European Union.

The unlikely partnership saw the two politicians share a platform at the launch of a "Britain Stronger in Europe" battlebus on Monday.

The key event was the unveiling of a Brexit 'guarantee card,' which will be handed out by campaigners around the country and outlines five things which will be guaranteed if Britain stays in the EU.

The pledges include:

• Full access to the EU's single market.
• The protection of workers' rights, including paid anti-discrimination laws and paid leave.
• A special status: never joining the Euro and having control over the UK's borders.
• Keeping the European Arrest Warrant.
• And stability for the UK.

Speaking at the event, Khan explained: "The vote in just 24 days time is one of the most important political decisions many of us will make in our lifetime. The stakes could not be higher."

"That's why I say to young people get involved, get registered, have your say and make sure you make a decision that will affect your future and the future of generations to come."

The unexpected act of reconciliation comes just weeks after the prime minister accused Sadiq Khan of having links to Islamic extremists during the London mayoral election.

However, the newly-elected mayor appears to have put their differences to one side for the sake of the EU referendum. While appearing on ITV's "Peston on Sunday," he said: "Is it in London's interests for the mayor of London to be at permanent war with the Conservative prime minister?"

"We're never going to be best friends, but what is important is that the mayor of London argues the case for London and for Londoners to remain in the European Union. This debate is far more important than David Cameron or me."

Khan isn't the first Labour politician to have shared a platform with David Cameron in a bid to keep Britain in the EU - both Harriet Harman and Tessa Jowell have spoken alongside the PM - but he is