BORIS JOHNSON is preparing to call for a “no” vote in Britain’s referendum on the European Union in an attempt to extract greater concessions from Brussels than David Cameron is demanding.

In a stance that puts him on a collision course with the prime minister, the mayor of London believes Britain should reject any deal Cameron puts forward because the EU will not give enough ground.

Johnson has told friends that a “no” vote is desirable because it would prompt Brussels to offer a much better deal, which the public could then support in a second referendum.

Johnson said: “We need to be bold. You have to show them that you are serious.”

The mayor’s views, shared with friends last week, will send shockwaves through