Andrew Mitchell to be David Cameron's Chief Whip

Andrew Mitchell will become the Government's Chief Whip today when David Cameron carries out his first full-scale reshuffle.

Mr Mitchell – nicknamed "Thrasher" when he attended Rugby public school for his strict discipline as head of a house – will move from his job as International Development Secretary. He will face a difficult task in trying to head off further rebellions by Conservative MPs increasingly critical of Mr Cameron.

Yesterday the Prime Minister's attempt to relaunch his Government ran into trouble when Tory right-wingers demanded a much more radical "pro-growth" strategy and his decision to set up an independent commission to consider a third runway at Heathrow Airport came under fire.

Mr Cameron will try to reassert his authority today by announcing a wider than expected reshuffle. He hopes a new generation of ministers will freshen up his Government. The most senior ministers – George Osborne (who was booed as he prepared to present medals at the Paralympic Games last night) William Hague and Theresa May – will keep their posts. But middle-ranking Cabinet ministers including Kenneth Clarke, Jeremy Hunt, Iain Duncan Smith and Justine Greening may be moved to other jobs against their wishes, while others such Andrew Lansley and Caroline Spelman could be sacked from the Cabinet.

Those winning promotion to the Cabinet are likely to include Grant Shapps, the Housing minister, who is expected to become Conservative Party chairman. David Laws, the prominent Liberal Democrat who resigned as Chief Treasury Secretary over his parliamentary expenses, will return to Government as an Education minister. Mr Mitchell will join the Cameron inner circle and is helping to shape the ministerial shake-up. He will replace Patrick McLoughlin, a former miner, who will be promoted to the Cabinet.

Last night the Prime Minister said Mr Mitchell had done "a superb job" and made "a real difference" at the Department for International Development, where he faced criticism from Tory MPs because his budget was exempt from cuts under Mr Cameron's flagship policy to boost overseas aid.