Boris Johnson 'to campaign for Brexit in EU referendum'
Boris Johnson has declared that he is to join the campaign for Britain to leave the European Union.
The London mayor put an end to months of speculation, saying that David Cameron's re-negotiation had failed to deliver fundamental change in Britain's relationship with Brussels.
"I don't think that anybody can claim that this is fundamental reform of the EU or of Britain's relationship with the EU," he said.
His announcement - made outside his London home - is a huge boost for the "out" campaign potentially giving them a popular figurehead able to connect with voters in a way few other Westminster politicians can manage.
At the same time, it comes as a bitter blow for David Cameron who had long believed that his old rival from their days at Eton and Oxford would ultimately fall in behind his EU re-negotiation package.
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Earlier British Prime Minister David Cameron issued a last-ditch appeal to Mr Johnson not to join the Brexit campaign, saying it would be a "wrong step" for Mr Johnson to link up with Ukip leader Nigel Farage and Respect's George Galloway in the "out" camp.
"I would say to Boris what I say to everybody else, which is that we will be safer, we will be stronger, we will be better off inside the EU," the Prime Minister told BBC1's The Andrew Marr Show.
"I think the prospect of linking arms with Nigel Farage and George Galloway and taking a leap into the dark is the wrong step for our country.
"If Boris and if others really care about being able to get things done in our world, then the EU is one of the ways in which we get them done."
Speculation that Mr Johnson is leaning towards the Leave campaign was heightened with the disclosure that he hosted a private dinner with Justice Secretary Michael Gove just days before he declared for out.
It raised the hopes of Leave campaigners that Mr Johnson will now provide the figurehead they have been looking for who can cut through to voters in a way that few other Westminster politicians can.
However Mr Cameron warned that while leaving the EU could create the impression that Britain was reclaiming its own sovereignty, in practice it would be an "illusion".
"If Britain were to leave the EU that might give you a feeling of sovereignty but you have got to ask yourself 'is it real?'," he said.
"Would you have the power to help businesses and make sure they weren't discriminated against in Europe? No you wouldn't. Would you have the power to insist that European countries share with us their border information so we know what terrorists and criminals are doing in Europe? No you wouldn't.
"If suddenly a ban was put on for some bogus health reasons on one of our industries, would you be able to insist that that ban was unpicked? No you wouldn't.
"You have an illusion of sovereignty but you don't have power, you don't have control, you can't get things done."