David Cameron has given the go-ahead to Boris Johnson to return to the Commons at the next general election before he has completed his second and final term as the Mayor of London.
The move would establish Mr Johnson, who won two standing ovations at the Conservative conference, as a leading contender to succeed Mr Cameron as party leader.
The Mayor has remained opaque about his plans, but the Prime Minister disclosed that they had discussed the possibility of Mr Johnson coming back as an MP in May 2015, a year before he leaves City Hall.
Mr Cameron said: “I’ve had this conversation with Boris and my message to him is ‘you’re a brilliant Mayor of London, you've done a great job, you’ve got a lot more to give to public life, and it would be great to have you back in the House of Commons at some stage, contributing to public life’.
“But that’s up to him, but I’ll certainly be giving him a warm welcome.”
Asked if he could return in 2015, Mr Cameron replied: “Absolutely, but that’s a matter for him. It’s his plan.”
Mr Johnson has been connected with a series of safe Conservative parliamentary seats which could provide a platform for his return to Parliament.
However, he has ruled out standing in Croydon South, where the Tory association will next week draw up a shortlist of possible candidates.
The Mayor admitted he was still “fudging” over whether he could return to the Commons in 2015, although he spoke last month of his regret of not being in the chamber in August when MPs debated military action in Syria.
Mr Johnson was mobbed by activists and television crews in Manchester as he made his annual visit to the conference.
Previous barnstorming appearances by the Mayor, with occasional swipes at Coalition policies, have been widely interpreted as laying down a marker for his leadership ambitions.
But today’s address was broadly loyal, apart from an appeal to Chancellor George Osborne to cut stamp duty on property sales, which he warned was “stamping on the fingers” of those who want to get on the housing ladder.
He also proposed tax breaks enabling employers to offer loans to staff to pay for their rental deposits, with the cost off-set against tax.
Mr Johnson invited controversy by backing the complaint of celebrity chef Jamie Oliver that British youths would not work as hard or as long as the Eastern European migrants who staff some of his restaurants.
He said the Government needed to tackle the problems of welfare dependency, educational under-achievement and low self-esteem which hold some young Britons back from fulfilling their “vast and latent” potential.
The Mayor said the problem of lack of motivation to work was being tackled by the efforts of the Work and Pensions Secretary, Iain Duncan Smith, to reform the welfare system and by Education Secretary Michael Gove’s drive to restore “rigour and realism” in schools.