By Belinda Goldsmith
LONDON (Reuters) - London's charismatic mayor, Boris Johnson, has dropped his strongest hint yet that he is interested in returning to national politics, with comments set to renew speculation over his ambitions to lead the Conservative party.
Johnson, known for his eccentric manner, sharp wit and unruly mop of blond hair, has long been tipped as a potential leader if the current incumbent, Prime Minister David Cameron, were to suffer a party coup or lose the next election in 2015.
Johnson's popularity soared ahead of Cameron's with London's successful hosting of the 2012 Olympics Games. A survey by pollster ComRes in June showed the mayor enjoying a favorability rating of 44 percent compared to 23 percent for the prime minister.
While pledging loyalty to Cameron, Johnson has made no secret of his ambition to succeed him if a vacancy were to arise. And the mayor told the FT (Financial Times) Magazine in an interview to be published on Saturday that last month's dramatic parliamentary debate on Syria had rekindled his desire to return to the front line of national politics.
"During the whole Syria thing, for the first time in years, I wished I was in parliament," Johnson, 49, told the FT, putting the party leadership on the agenda ahead of the Conservative's annual party conference starting on Sunday.
"I watched that and I thought .. I wished, I wished."
Cameron lost the parliamentary vote, which blocked Britain from joining any military strike on Syria - a damaging blow to the prime minister's standing at home and abroad.
Johnson's comments will serve as a reminder to Cameron that he has a popular rival at his shoulder as he tries to rebuild his authority, while confronting discontent within the party over issues such as immigration, gay marriage and membership of the European Union.
To return to national politics, where he served from 2001 to 2008, the mayor would need to win a parliamentary seat in a general election or a by-election, which is triggered when a lawmaker dies or resigns.
With his current mayoral term due to run until 2016, he has ruled out standing in the 2015 general election, even though a number of Conservative politicians are said to be willing to stand aside to give him a way into Westminster.
But he has left his options open after 2016, with friends telling the FT that he was weighing up the prospects of fighting for the party leadership after Cameron steps down, and ahead of a 2020 election.
Johnson, who won mayoral elections in 2008 and 2012, reaffirmed that he would not seek a third term in charge of the capital. "I've said never," he said. "I think you have to be realistic about your political lifespan."
The rivalry with the prime minister goes back to their years at elite boarding school Eton College, where Johnson was two years ahead of Cameron. Both went on to Oxford University.
Cameron has often laughed off suggestions that Johnson could replace him, once describing the mayor as a "blond-haired mop sounding off from time to time".
Johnson said his only priority now was to help "Dave" get re-elected as prime minister.
Using a rugby metaphor, as he often does, when asked about his leadership ambitions, he said that "if the ball came loose from the back of the scrum" he might try to grab it.
"The ball is currently at the feet of the scrum. I am bound into the pack and we are surging towards the line for a pushover try. That's my role: bound in, driving for the line."
(Editing by Mark Trevelyan)