Cameron to buy Boris EU vote with Cabinet job

The move to bring Johnson onside has led to speculation that the Prime Minister is on the verge of a deal with EU government leaders to be signed off at a summit next month.

This would mean Mr Cameron can go back to British voters and lead a campaign to stay in the EU with the referendum in July or September. According to party sources, Johnson could be offered a senior Cabinet job as early as February, when Cameron hopes to complete his renegotiation.

The London Mayor, who steps down in May, has been flirting with leading the exit campaign and joining Eurosceptic Cabinet members like Work and Pensions Secretary Iain Duncan Smith, Home Secretary Theresa May and Justice Secretary Michael Gove.

However, it is understood that the price of a Cabinet job for Johnson would be to loyally support Cameron in an EU referendum, which must take place before the end of 2017.

Poland says it will make a deal allowing the UK not to give EU immigrants benefits for the first four years. The offer is a Polish U-turn over Cameron’s key demands in renegotiating Britain’s EU membership, which have already been dismissed as “unambitious” and “vague” by those wanting to leave.

Polish foreign minister Witold Waszczykowski has said that a deal could take place if the UK helps to bolster Nato forces in his country.

But Matthew Elliott, chief executive of Vote Leave, said: “None of what is being considered will take back control or return powers to Britain. The only safe option is to Vote Leave.”