The In campaign launches – with David Cameron there in spirit if not in name

Officials at No 10 have already held meetings with leaders of the campaign to stay in Europe

Senior figures in Downing Street have held unofficial talks with leaders of the campaign to keep to Britain in the European Union, and given their backing to Tory peers who have come out in favour of Britain’s membership.

While publicly maintaining that the Government is “entirely focused on a successful renegotiation”, figures close to the Prime Minister are understood to have held discussionswithAndrewCooper, the former Downing Street aide who is now a leading figure in the “in” campaign.

Downing Street also privately endorsed the decision by the Conservative peer and businesswoman Karren Brady to take a leading role in the Britain Stronger In Europe campaign, which was launched yesterday. The group is also being chaired byanother Tory peer, the former Marks &Spencer boss Lord Rose.

While Downing Street does not want to be seen to be prejudging the outcome of European negotiations, it wants to ensure that the pro-EU campaign is in a strong position for when a deal is struck.

Asked about what discussions had been taking place between Number 10 and the “in” campaign, a source said that Downing Street was having “lots of conversations with lots of people”. They did not deny that Lord Rose and Baroness Brady’s roles had been officially sanctioned.

But underlining Tory divisions on Europe the central message of the “in” campaign launch yesterday was undermined by Boris Johnson, who has repeatedly refused to rule himself out as a possible leader of the “leave” campaign.

Speaking on a visit to Japan, Mr Johnson claimed that the price of Britain quitting the European Union was “lower than it’s ever been”.

While he maintained that his position was the same as that of David Cameron, his remarks will be widely interpreted as leaving the door open for him to campaign against Britain’s membership following any renegotiation, in the hope that a vote to leave would force the Prime Minister from office and undermine George Osborne’s chances of succeeding him.

“I think I am exactly where the Prime Minister is and, I think, actually a huge number of the British public,” he said.

“We want, in an ideal world, to stay in a reformed European Union, but I think the price of getting out is lower than it’s ever been. It’s better for us to stay in, but to stay in a reformed EU. That’s where I am.”

At the launch event in east London for the Britain Stronger In Europe campaign, the former police chief Sir Hugh Orde said the country could be viewed as a safe haven by international criminals if the country voted to end its relationship with Brussels.

He was joined by business leaders who said Britain would be economically less secure outside the union and that a vote to leave could costs both jobs and prosperity.

Sir Hugh, a former president