David Cameron has handed a prized promotion to Boris Johnson's younger brother.  The Mayor of London's musings have proved to be a regular annoyance to the Prime Minister since he took office. But in an apparent attempt to keep at least one Johnson on side, he has made Jo Johnson, who entered the Commons at the last election, the Parliamentary Private Secretary to Mark Prisk, the Business Minister

The move will see the MP for Orpington, a former investment banker and respected financial journalist, assist a ministerial team tasked with finding ways to nurse the economy back to health.

Finding jobs for the talented members of the 2010 intake has proved a headache for Tory whips. The need to hand Government posts to Lib Dems as a result of the coalition has meant spare positions have been few and far between.  Louise Mensch, the vivaciousTory MP for Corby, joked in a magazine interview this week that she needed to ask the party whips what she needed to do to be given a PPS job.

However, Mr Johnson has impressed the leadership with his compelling defence of the City of London and his willingness to speak up about the need to safeguard Britain's trading relationship with Europe.  Boris Johnson, seen as the main rival to George Osborne as the next Tory leader, pleased the Tory grassroots last month by pushing for a referendum on a new EU Treaty.

By contrast, his brother argued it would be "counterproductive" to go to war with Britain's European partners. He argued that Britain should be attempting to persuade Paris and Berlin that the City's strength was an asset to Europe in its quest to compete with New York and Asia.  A Whitehall source confirmed Mr Johnson's appointment, adding the decision had been made some time ago.

A post became free after Aidan Burley, the former PPS to Justine Greening, the Transport Secretary, was sacked after being pictured with a man dressed as a Nazi officer at a stag do. A Tory spokesman confirmed his job has now been filled by Andrew Jones, the MP for Harrogate and Knaresborough. In turn, Mr Johnson has taken up Mr Jones' old post.