Boris’s brother heads Cameron’s policy team

The Prime Minister announced that Orpington MP Jo Johnson had been appointed as a Cabinet Office Minister, and handed the key post in Downing Street.

Meanwhile, it is understood that Mr Hilton will meet with a new advisory board of Conservative backbenchers “a few times a year” to help develop and push through Conservative policies.

However, sources stressed that he was not returning to a formal job and and is not expected to move back from California. He has already been informally advising the premier.

Mr Cameron gathered the board – including his former press secretary George Eustice, Jesse Norman, who led the House of Lords reform rebellion, and ex-Cabinet minister Peter Lilley – for the first time this morning.

“I told them I want more ideas to help hardworking people,” Mr Cameron posted on Twitter afterwards.

Mr Johnson will carry out the unpaid role alongside his paid duties as a Government whip. It is not clear whether he will be called on to answer questions in the Commons.

The premier’s spokesman batted away questions over whether appointing another Eton-educated figure meant he was receiving a “narrow” range of advice. “The Prime Minister is never short of advice from people across the spectrum,” the spokesman said.

Sources said the policy advisory board would benefit from Mr Hilton’s experience of developing and implementing policy. The creation of the group opened an opportunity to make his involvement “a bit more formal”.

Nick Gibb, Jane Ellison and Paul Uppal are also serving on the Tory board.

The changes are intended to make the Number 10 operation more political ahead of 2015, and echo the arrangements in place when Baroness Thatcher was in power. It is also the latest effort to strengthen lines of communications with restive Tory backbenchers after right-winger John Hayes was recruited to Downing Street as a “sounding board” last month.