David Cameron today announced changes to his ministerial team, with Michael Fallon adding responsibility for energy to his brief in the business department.
Former energy minister John Hayes becomes the Prime Minister's senior parliamentary adviser, leaving a department where he has publicly clashed over policy with the Liberal Democrat Secretary of State Ed Davey.
The move leaves Fallon as the senior Tory in two departments led by Lib Dems, under Davey at Energy and Climate Change and Vince Cable at Business, Innovation and Skills.
Hayes becomes a minister of state without portfolio in the Cabinet Office and has been appointed to the Privy Council, said Number 10 in a statement.
A source said Fallon's appointment would give energy "a stronger business focus", and insiders were playing down any suggestion that it signalled a shift in the Conservative approach to wind farms, on which Hayes is a noted sceptic.
It is understood that Cameron wants Hayes to play the "greybeard" role previously undertaken by Fallon, as a senior, respected and trusted link between the parliamentary party and Number 10.
The move was being seen as a promotion for South Holland MP Hayes, who will be at the heart of 10 Downing Street and will attend the Prime Minister's daily 8.30am and 4pm meetings.
It will be seen by Westminster watchers as an attempt to steady nerves among Tory backbenchers spooked by poor poll ratings and the sluggish economic recovery.
Tory insiders admit that there has been a gap in that side of operations since Fallon was moved from deputy chairman of the party to take up a ministerial role last year.
There is little secret that Davey had a difficult relationship with Hayes during his six-month stint at the Department for Energy, though it is not thought that this was the primary reason for his move.
In a message on Twitter, Cameron said: "Delighted John Hayes joining me as a Senior Parliamentary adviser - and Michael Fallon adding a key energy role to his brief."