Chancellor George Osborne has said government departments have found an extra £4.5 billion for the current financial year.
George Osborne has set out his plans to help restore Britain's economy by staging the biggest ever sell-off of government and public owned corporate and financial assets this year.
The Chancellor will create a new government-owned company who will be in charge of the sales, which are expected to be worth £23 billion.
UK Government Investments (UKGI) will sell shares in Lloyds Banking Group, UK Asset Resolution assets, Eurostar and the pre-2012 income contingent repayment student loan book.
ITV News Political Editor Tom Bradby reports:
It is part of plans to cut spending by £13 billion by 2017/18.
Speaking at the Confederation of British Industry (CBI), Osborne said: "If we want a more productive economy, let's get the government out of the business of owning great chunks of our banking system - and indeed other assets that should be in the private sector."
A "plan to make Britain work better" will be published over the next few weeks, setting out proposals to improve transport, broadband, planning, skills, ownership, childcare, red tape, science and innovation.
Osborne also addressed the issue of the EU referendum saying he will be "fighting to be in Europe but not run by Europe".
George Osborne will set out the government's plans to balance the books and overhaul welfare when he delivers the first all-Tory budget on 8th July.
The financial package would focus on "working people" and turning the Conservatives' election promises "into a reality", Chancellor Osborne said.
Announcing the date in an article for The Sun rather than the more conventional method of a statement to Parliament - which is not yet sitting - Mr Osborne said: "On 8th July I am going to take the unusual step of having a second Budget of the year - because I don't want to wait to turn the promises we made in the election into a reality...
"And I can tell you it will be a Budget for working people."
Treasury aides indicated the Summer Budget would set out the Government's plan to deliver savings promised during the election campaign, and pay down Britain's debts in a "fair and balanced way".
Mr Osborne is expected to give more details of how ministers intend to shave £12 billion a year from the welfare bill while protecting the most vulnerable.
Chancellor George Osborne has outlined "a radical new model of city government" for major English cities to take control of their own affairs if they agree to be governed by a directly elected mayor.
Speaking in Manchester, he said: "We will hand power from the centre to cities to give you greater control over your local transport, your housing, your schools, your healthcare and we'll give you the levers you need to grow your local economy and make sure local people keep the rewards.
"With these new powers for cities must come new city-wide elected mayors who work with local councils.....I will not impose a mayor on anyone but nor will I settle for less. My door is open to any other major city who wants to take this bold step into the future".
"This is a revolution in the way we govern England", Mr Osborne added.
It is time for major cities in England to take control of their own affairs, the Chancellor will declare later today, but they will need to accept Mayors to do so.
George Osborne will explain that cities will be given power over local transport, housing, planning, policing and public health.
Mr Osborne has previously said devolution must go hand-in-hand with the establishment of an elected mayor.
Today he is expected to reiterate that, saying people must have a "single pointy of accountability."
Manchester is the first city set to benefit from extra powers, with plans for an elected "metro mayor" for the whole of the Greater Manchester region.
Describing the new law as a "bold step", Mr Osborne will say he is open to approaches from other cities wishing to follow the same route.
There are suggestions that George Osborne could be in line for the Deputy Prime Minister job as he makes his way to Downing Street this morning.
David Cameron will be able to choose all his own Cabinet Ministers if he is able to form a majority government as predicted.
During the last Government ministers jobs were shared with coalition partners the Liberal Democrats, with leader Nick Clegg as Deputy Prime Minister.
George Osborne has tweeted that David Cameron has given the "performance of a lifetime" during his Question Time appearance.
David Cameron just gave the performance of a lifetime - strong, personal and profoundly optimistic about Britain's future
The Chancellor George Osborne has insisted that it's good news that the economy is growing, even though the latest figures are half as strong as at the end of 2014.
ITV News Economics Editor Richard Edgar spoke to George Osborne this morning: