When David Cameron and Boris Johnson met at the Chequers country retreat last Sunday, they hoped to clear the air after a summer marked by tensions and rivalry. But any hope that the peace talks – which included a pub lunch and football with the children on the lawns – had quelled pre-conference disquiet disappeared on Thursday, when the London mayor launched another scathing attack on the government’s “lamentable” handling of the future of Heathrow airport.
Mr Johnson has been an increasing annoyance to the prime minister ever since the Olympics, which gave a turbo-boost to the mayor’s popularity and offered numerous opportunities for him publicly to upstage Mr Cameron. Since then there has been a crescendo of media speculation about the London mayor’s ambitions while Conservative MPs anxious about the party’s future are muttering about Mr Johnson as a prime ministerial challenger.
Nadine Dorries – a Tory backbencher who has never tried to hide her dissatisfaction with the leadership – is already a public cheerleader for Mr Johnson. Another MP points out that Mr Johnson’s strength is being able to present right-of-centre policies “in a way that doesn’t frighten the horses”.
“He’s like a sort of political alchemist, and can say things that from the mouths of Cameron and Osborne sound nasty,” the backbencher says.
Despite the obvious temptation to try to bolster support during the Tory party conference, Mr Cameron’s allies believe that Mr Johnson will toe the line. Any show-stealing disloyalty would be seen in a dim light by Tory activists, even if some of them are infatuated with the mayor.
“Even if you are having a relationship with an interloper and find them rather romantic, you still want them to behave well in front of the family,” said one Cameroon. “They can save the naughty stuff till later.”
But even if Mr Johnson does exercise sensitivity next week, his winter schedule may give the prime minister cause for alarm. In the first week of November, the mayor will address the Tories’ 1922 committee of backbench MPs on his re-election earlier this year, which will provide a chance to build his political base in Westminster. Later in the month, his “world statesman” tour of India is unlikely to damp speculation that he is preparing a bid for the top job. Mr Johnson is expected to burnish his foreign policy credentials further at the annual meeting of the world’s powerbrokers in Davos, Switzerland, in February, and a trip to China is in the pipeline for 2013.
Mr Cameron insists he gets on well with Mr Johnson and that he is delighted to have in his party a figure capable of winning two elections in Britain’s biggest city, especially when it is often seen as a Labour stronghold.
Some say the prime minister has even encouraged Mr Johnson to return to parliament, although he is unlikely to welcome the suggestion by some Tory MPs that the mayor should stand in a by-election before 2015, putting him in pole position in the event of a Tory election defeat.
Sonia Purnell, the mayor’s biographer, is wary of reports that Zac Goldsmith, Tory MP for Richmond, offered Mr Johnson his own seat. But she admits that it is widely acknowledged by Tories that if he were to try to return to parliament before the next election he would have to find a seat in the capital to avoid criticisms of “desertion”.
“That way, he can argue that he is merely representing their interests in parliament – not least the campaign to prevent the building of a third runway at Heathrow,” Ms Purnell says.
For now the prime minister’s supporters are sanguine about any threat from the London mayor. After all – the previous occupants of Number 10 have had to contend with rivals on the backbenches or even around the cabinet table, not from a figure who is not even an MP.
Additional reporting by James Pickford
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