Whitehall sources suggested that, while things can change at the last moment, Monday and Tuesday were being set aside for the Prime Minister's first major shake-up of his team.
With both the Tories and the Liberal Democrats falling in the opinion polls, the economy in a slump and Mr Cameron's leadership under fire from his own back benches, the PM will be determined to hit the ground running after summer recess.
Because the UK Government is made up of two parties, Mr Cameron's task in changing his frontline team is made all the more difficult.
None of the LibDem Cabinet ministers, such as Business Secretary Vince Cable and Chief Secretary to the Treasury Danny Alexander, are expected to be moved. The main changes will come lower down.
David Laws, who resigned just weeks into his job at the Treasury over an expenses scandal, will return, possibly with a roving brief on social policy based in the Cabinet Office. Reports that Jo Swinson could replace Michael Moore as Scottish Secretary have been roundly rubbished in Whitehall. But Nick Clegg's aide could be moved to another department, possibly replacing Lynne Featherstone as Equalities Minister.
On the Conservative side, Justice Secretary Ken Clarke is expected to stay in his role.
Housing Minister Grant Shapps is strongly tipped for the job of the new Tory Chairman. He would replace the two current co-chairmen, Lord Feldman and Baroness Warsi.