Speculation is mounting about an imminent ministerial reshuffle as MPs return for a new parliamentary term.
The reshuffle, which could come as early as Tuesday, would be the first major changes to David Cameron's top team since he became prime minister.
Although high-ranking ministers like the chancellor are unlikely to be affected, changes are expected in the cabinet and junior ministerial posts.
It comes as the government announces further measures to boost growth.
On Sunday, Mr Cameron said he wanted to "cut through the dither" that was holding the British economy back - amid growing unease among Conservative MPs about a lack of a plan to get the country out of recession.
The government will underwrite up to £50bn of private sector building projects which need finance.
The Treasury said the The Infrastructure (Financial Assistance) Bill, which builds on a scheme launched in July, will give the green light to £40bn of construction projects by using the government's low interest rates to underwrite them.
Ministers are also expected to set out plans to underwrite construction of up to £10bn worth of new homes, including guaranteeing the debt of housing associations and private sector developers.
'Conservative drive'In addition, the government will legislate to speed up planning decisions and encourage development of Green Belt land, if certain conditions are met.
But senior backbencher David Davis, who lost a leadership contest to David Cameron in 2005, will call for a totally different approach in a speech later - based around deeper reductions in spending cuts and tax cuts.
BBC chief political correspondent Norman Smith said the reshuffle was about party management as Mr Cameron tried to relieve some of the unease amongst his own backbenchers.
He said there was a perception amongst some Tory MPs that the prime minister was lacking in "Conservative drive" and the government needed a more traditional Tory outlook.
The BBC understands the reshuffle is unlikely to affect Chancellor George Osborne, Home Secretary Theresa May and Foreign Secretary William Hague. But former Liberal Democrat cabinet minister David Laws is expected to return.
Mr Laws resigned as chief secretary to the Treasury two years ago after admitting he claimed expenses to pay his partner's rent.
Conservative Party chairman Baroness Warsi this weekend appealed to David Cameron to allow her to keep her post in any reshuffle.
She said she would like to "stay doing what I'm doing" and argued that as a northern, female Muslim she could help the party attract a new generation of voters.
There has also been speculation about possible moves for Justice Secretary Ken Clarke, Welsh Secretary Cheryl Gillan and International Development Secretary Andrew Mitchell - with Grant Shapps, Chris Grayling and Maria Miller among Conservative ministers tipped for promotion.
