David Cameron
Cameron held a late-night press conference in Brussels after clinching a new deal on the UK's EU membership Reuters

Prime Minister David Cameron admitted he was 'sad' that some of his closest allies will be campaigning for Britain to leave the EU but denied that he is losing his campaign, claiming that even his biggest political opponent, Labour leader Jeremy Corbyn, is on his side. Cameron was appearing on the Andrew Marr show on the BBC on 21 February, as he started his campaign to keep Britain in the EU after announcing the date of the referendum as 23 June, the previous day.

On the day of the announcement, seven members of his lined up against Cameron, including close ally Michael Gove. Boris Johnson, London mayor and MP for Uxbridge and South Ruislip, is also expected to support the 'Leave' campaign.

Cameron said: "Of course I am sad that a close friend of mine, Michael, is on the other side of this argument. What I would say to him – and Boris – is that the prospect of linking arms with George Galloway and Nigel Farage is a leap into the dark. You always have people who think we will be better off out."

Cameron calls on Corbyn's support

When Marr suggested Cameron was already losing the argument as well as key members he answered: "I don't think we are losing this. I would say many things about Jeremy Corbyn but I would never describe him as a member of the establishment, but he is on my side."

Cameron insisted that the crucial cabinet meeting was 'civilised' despite the dissenting voices, and said he would start his campaign for the referendum stressing the message that Britain will be 'stronger and safer' as a member of the EU.

"I care about Britain being able to stop stuff, standing up to Vladimir Putin, Iran, having that table inside the EU, this is about our national interest. We'll be better off in, and I'll be taking that message round the country for the next four months. This is a hard-headed calculation. How do you stay strong with Isil [Islamic State] to the south and Putin to the east?"

PM will not quit

The PM did admit that his negotiations were not completely successful, losing out on key points such as benefits for migrants, one of Gove's particular bugbears. Cameron admitted: "I love this country very passionately – I do not love the institutions of Brussels. But it's to get the best of both worlds in this amended EU that I have fought for."

The prime minister stressed though that if the referendum goes against him he will remain as PM. "I stood on a promise I made three years ago. Now we make the commitment and the people will decide. I will meet their instruction."