Chancellor George Osborne will set out details of the new coalition Government's first £6 billion of public spending cuts to be made this year.
Whitehall travel, IT projects, quangos, outside consultants, and new recruitment to the Civil Service will all be hit as Mr Osborne and Treasury Chief Secretary David Laws make their first inroads into Britain's record £156 billion deficit.
The Liberal Democrats signed up to the Conservative plan as part of the coalition deal between the two parties, despite having opposed spending cuts this year during the election campaign.
Deputy Prime Minister Nick Clegg said that his party accepted the need to act now because of the turmoil in the eurozone caused by the Greek debt crisis. He said that the coalition would need to hold its nerve as it pushed through the "painful" measures needed to deal with the "great black hole" in the public finances left by Labour.
He said: "The age of plenty where money could be thrown around in almost carelessness, which is what the outgoing Labour government has done for some time now, is over. There are going to be difficult decisions, they are going to be unpopular decisions, they are going to be controversial, we are going to have to hold our nerve."
However TUC general secretary Brendan Barber warned that the economy remained "extremely fragile" and that starting cuts this year would jeopardise the recovery.
Mr Osborne said that the "great majority" of the savings this year will be used to start paying down the deficit. Press reports over the weekend suggested that £513 million of savings will come from a "bonfire of the quangos" - with organisations like the Qualifications and Curriculum Development Agency set for the axe.
The Sun reported that Child Trust Funds, a scheme started in 2002 entitling every child to a £250 voucher to be invested on their behalf, are to be scrapped to save £580 million a year.
Vince Cable's Department for Business, Innovation and Skills looks set to be one of the big losers, with reported savings of £900 million, while a further £200 million could come from university funding and a freeze on Civil Service recruitment is expected to save another £163 million.
It is reported that the Treasury identified further savings from Whitehall's annual £3 billion travel bill - including £125 million on taxis, £320 million on hotels and £70 million on flights. Further savings could come from the £1 billion spent on government advertising and the £580 million budget for office furniture.