The south Lincolnshire MP John Hayes is leaving the energy department to become the Prime Minister's senior parliamentary adviser.
Mr Hayes, the MP for South Holland and The Deepings, publicly clashed over policy with the Liberal Democrat Secretary of State for Energy and Climate Change Ed Davey.
Conservative Michael Fallon has now added responsibility for energy to his brief in the business department.
John Hayes will become a Minister without Portfolio based in the Cabinet Office. He will also be appointed to the Privy Council.