HOW HE PLEDGED LOYALTY TO ALL THREE CONTENDERS TO SUCCEED MRS T

WHO was most likely to be the next Tory Prime Minister? When Margaret Thatcher resigned in 1990, Cameron clearly decided to hedge his bets.

At the time, he was one of the bright young Turks working in Conservative Central Office, along with his future Culture Minister Ed Vaizey and Ed Llewellyn — his future chief of staff.

In the aftermath of the resignation, staff were under strict instructions to remain neutral during the leadership contest, and banned from helping candidates during office hours.

But the rule didn’t prevent them visiting the contenders in a strictly observational capacity, or volunteering for campaign teams at the weekend. The first to pitch up at John Major’s campaign headquarters, just off Smith Square, was Ed Vaizey.

‘Sorry I can’t do anything to help now, but I just wanted to let you know I’m supporting you,’ he told them cheerfully, adding that he’d make himself available that weekend. Next, Cameron and Llewellyn turned up together. Like Vaizey, they offered warm words of support and made noises about pitching in as soon as they could. That weekend, however, only Vaizey arrived at Major’s campaign headquarters.

Long after the leadership contest was over, Major’s supporters discovered the pair had delivered the same warm words to Michael Heseltine and Douglas Hurd, leaving all three contenders under the illusion they enjoyed their support.

Smart, fly — or both? Admirers will see the episode as the mark of an astute political operator, ready to work with anyone who could further his aims. Detractors will interpret it as evidence of a lack of principle and a willingness to deliberately mislead others for his own ends.

In any case, it worked. After Major won, Cameron was invited to help prepare him for Prime Minister’s Questions. It was an incredible opportunity. Aged just 24, he now had one-to-one access to the Prime Minister, and was already gaining an insight into the inner workings of Downing Street.

Several newspaper diary items suggested that young Cameron was responsible for improving Major’s normally lacklustre performances.