David Cameron's new Cabinet will meet for the first time, following a reshuffle which has been widely regarded as marking a shift to the right.
Mr Cameron replaced liberal Justice Secretary Kenneth Clarke with Chris Grayling, while making Jeremy Hunt Health Secretary.
Caroline Spelman was sacked as Environment Secretary in favour of Owen Paterson, a right-winger with a much more sceptical approach to subsidies for renewable energy.
The five Lib Dem Cabinet ministers all retained their posts, but Business Secretary Vince Cable saw former Conservative co-chairman Michael Fallon installed as a "voice for business" in his department and Chancellor George Osborne's ex-chief of staff Matthew Hancock handed a junior ministerial role.
Further changes to junior posts in the Government were due to be announced later, with Mr Cameron expected to appoint members of the 2005 and 2010 intake of MPs as part of a bid to rejuvenate his administration with fresh faces from the back benches.
The new Cabinet will meet after Prime Minister's Questions at 10 Downing Street on Wednesday afternoon.