David Cameron has recruited billionaire entrepreneur Sir Philip Green to lead a review of Government spending, it has been announced.
Sir Philip, owner of clothing retailer Arcadia Group, will scrutinise expenditure from the past three years to try and identify where savings can be made.
The conclusions from the external review will feed into the Comprehensive Spending Review, which is due to be completed in October.
Announcing the appointment, Cabinet Office minister Francis Maude said: "We are extremely fortunate to have Sir Philip, with his immense commercial experience and of course his fantastic track record at managing large organisations, on board.
"Sir Philip has made clear to the Government the importance of his business remit, which has always been that efficient operating is different from cost cutting and removing jobs."
Sir Philip, who will be supported by a team of civil servants and report to Mr Maude and Chief Treasury Secretary Danny Alexander, said: "I will give this efficiency review my very best effort knowing how hugely important it is to the recovery of the country.
"I want to help focus, motivate and energise to achieve these efficiency savings. It is these actions that will re-start growth in the UK."
Mr Green suggested a centralised system of buying for Whitehall could benefit the public purse.
He told BBC Radio 4's Today programme: "We need to get ourselves focused on the big spending, where is the money actually being spent. I think in the past, occasionally having had discussions on this, there is not central procurement. So the thought process of us having an individual buyer in each one of our stores without centralising purchasing, will give you some idea hopefully of the opportunity."
Mr Green also said he had "no idea" what savings he could deliver, adding: "I don't know how much I can save because I don't know what is spent on what - that's what we've got to go and find out."