Government office premises and buildings that are under-used or empty will be offered as business space to entrepreneurs, David Cameron will announce.
The plan will be launched during a visit to the north-east where the PM is due to address a group of entrepreneurs on Monday.
Cameron will say that the government has a huge stock of buildings at its disposal.
"The first priority for the ones we aren't using is to sell them off, but in the meantime, many are going to be sitting idle. So let's match the capacity we've got with the need that's out there. Let's provide office space where we can to those who can use it," he will say.
The government hopes to offer more than 300 premises at low rates for one year so new companies can establish themselves and small firms can benefit from cheap deals.
With cuts to the public payroll, many government buildings lie empty or have space available as they await buyers.
As well as helping entrepreneurs, the initiative will give a much-needed boost to Treasury finances, officials claim.
Cameron is expected to say: "I said 2012 has got to be the year we go for it, the year we light new fires of ambition in our economy, the year we get behind Britain's grafters, doers, hard-workers and entrepreneurs.
"This isn't something we'd quite like to do – it's something we've got to do because enterprise is critical to this country's future.
"Enterprise is what we do in Britain. This is the year that, more than ever, we've got to go for it."
The PM will also launch a campaign aimed at encouraging people to believe "there is a business in everyone".
The Business in You initiative will see companies hold workshops and give advice on tackling some of the issues faced by employers. The scheme will be highlighted through adverts throughout the year on radio, billboards and in newspapers.
