Senior Liberal Democrats are among the biggest casualties of a coalition reshuffle, with Scottish Secretary Michael Moore and Home Office minister Jeremy Browne both losing their jobs.
Deputy Prime Minister Nick Clegg wielded the knife as David Cameron moved to promote more women and northern MPs to his Conservative team.
With just a year to go before the crucial referendum on independence north of the border, Mr Moore's Cabinet post was handed to Lib Dem chief whip Alistair Carmichael. Mr Clegg is believed to want a more attacking approach against Scottish first minister Alec Salmond.
In one of the biggest shocks so far, Mr Browne - on the right of the party and touted by some as a future leader - was also replaced by transport minister Norman Baker.
Exchanging letters with Mr Browne, Mr Clegg said it was "always very difficult to move colleagues out of government".
"But as you know, I have always been keen that we provide the opportunity for as many in our ranks as possible to contribute their skills to ministerial office during this Parliament so that, just as the Government has benefited from your contribution over the past three years, it can also gain from those of other colleagues in the remaining years of this Parliament," he wrote.
In his response, Mr Browne insisted he remained "supportive of the Government".
"I hope the Government will continue to strive to be reforming and innovative and avoid the danger of lapsing into transactional trade-offs and deferred decision making," he added.
Mr Moore told the BBC he was "disappointed" to be leaving office but "very pleased at what I have been able to achieve in the last couple of years".
Meanwhile, Mr Cameron has avoided changes to his Cabinet - but handed promotions to women MPs including Esther McVey and N icky Morgan.
Ms McVey has been pushed up the ranks at the Department for Work and Pensions to become employment minister, while Ms Morgan goes from assistant whip to Economic Secretary to the Treasury.
Allies of Chancellor George Osborne have fared well, with Sajid Javid made Financial Secretary to the Treasury, Matthew Hancock becoming skills and enterprise minister, and Greg Clark installed as Tory deputy chief whip.
Mr Clark has been moved from the Treasury to take on responsibilities for cities and constitutional reform at the Cabinet Office, and Andrew Robathan made Northern Ireland minister replacing Mike Penning - who takes on duties at the Department for Work and Pensions.
There was bad news for some long-serving Tories, with Mark Hoban ousted as employment minister after a 10-year spell on the party's front bench.
Another Tory, Mark Prisk, posted: "Asked to step aside from Housing for a younger generation. Disappointing but it's been a great eleven years on front bench."
Richard Benyon, an early supporter of Mr Cameron's Tory leadership bid in 2005, confirmed that he had stepped down as environment minister.
"On back benches! 3 and half really fun years with much achieved. Really appreciate time working with outstanding Ministers and Officials," he wrote on Twitter.
Labour leader Ed Miliband is also preparing to make changes to his top team.