Greg Barker is the frontrunner to be appointed to the Shadow Cabinet as part of a reconfiguration of the Conservative frontbench.

Although the scale of the changes made by David Cameron is unknown, he will almost certainly create a new post to shadow Ed Miliband.

On Friday it was announced that he will be the first Secretary of State for Energy and Climate Change.

The new department will take over the energy duties of the Department of Business, Enterprise and Regulatory Reform and the climate change responsibilities of the Department for the Environment, Food and Rural Affairs.

Mr Barker, 42, is Shadow Climate Change and Environment Minister and a close ally of David Cameron.

He accompanied the Tory leader on his trip to the Arctic in 2006.

The Sunday Telegraph reports that major Conservative party donor Lord Ashcroft has been compiling information on the performances of the Shadow Cabinet.

“The Tory deputy chairman has conducted detailed private polls and focus groups and established that the Tories are ahead in every area apart from international development, where they are 20 points behind,” the paper reports.

Shadow International Development Secretary Andrew Mithcell is thought to be in danger, with rising star Ed Vaizey tipped to replace him.

Other high-flyers from the 2005 intake who may be promoted or moved to a more prominent role include Grant Shapps, Jeremy Hunt and Maria Miller.

It is generally assumed this will be the last major reshuffle before the next general election, which must be called by June 2010.

Prime Minister Gordon Brown reshuffled his Cabinet on Friday, bringing Peter Mandelson back from Brussels and into the Cabinet as Business Secretary. Details of the changes to the junior ranks of ministers have not all been released.

Conservative Party Chairman Caroline Spelman’s position is the subject of speculation.

Despite being well-regarded in the party, it emerged earlier this year that she used parliamentary allowances to pay her nanny, claiming she also did secretarial work.

Mr Barker’s closeness to Mr Cameron was demonstrated in 2006.

A backer of Mr Cameron’s bid for the leadership, Mr Barker was mired in a tabloid feeding frenzy when it emerged he had separated from his wife and begun a relationship with a man.

The party leader gave him his full public support.

Gay rights campaigner Peter Tatchell accused the British press of being “sensationalist” in its treatment of Mr Barker’s marriage break up.

The press pursued the story vigourously, speaking to his mother-in-law, neighbours, and friends of his new partner.

Since coming out, Mr Barker has been supportive of causes important to the gay community and is to host a reception for the National Aids Trust at the Houses of Parliament later this week.