Ministers will announce a package of spending on new roads and other infrastructure projects next week in an effort to get more money and jobs into the economy.
Some of the building schemes in the national infrastructure plan are to be brought forward, under the proposals being drawn up by the Treasury with help from the Department for Transport.
The package will include direct government spending initially planned for later years, so that the government will not have to take on extra debt. It should also include details of new funding from the private sector.
Ministers also hope this and a series of other policies to be announced as MPs rise for their summer recess will help steer attention away from the dispute over reform of the House of Lords.
Among the schemes that will be pressed on ministers as being the most important for regional growth and competitiveness are a new toll road parallel to the A14 from Felixstowe docks to the Midlands, widening the A303 from the M3 to the south-west of England, widening parts of the A21 in Kent, and the Hastings bypass on the south coast in East Sussex.
The coalition has been under growing pressure from across the political spectrum and senior business figures to focus less intensely on spending cuts and adopt a plan B to spend more money directly in the economy. Officials can also argue, however, that because the investment was already planned it is closer to being a "Plan A-max".
The foundations of the announcement were laid by the prime minister in March, when he made a speech calling for more roads to be built and urging pension funds and sovereign wealth funds to get involved in financing the schemes. Officials have also been exploring infrastructure bonds – similar to standard government bonds but dedicated to infrastructure projects.
Cameron said infrastructure was the "magic ingredient in so much of modern life", adding: "It affects the competitiveness of every business in the country; it is the invisible thread that ties our prosperity together."
He added: "It requires private money, but it also requires political support and stability – for the creation of what Adam Smith taught us to see as public goods. So when it comes to the question of financing, we need to use the power of the state to unlock the dynamism of the market."
However, progress on pulling together a list of schemes is thought to have been hampered by uncertainty about how the projects would be paid for longer term after the PM ruled out tolls on "existing roads". Income to repay the debt is expected to be a mixture of national tax income, local taxation such as business rates, and potentially tolls on new roadspace.
In November the RAC Foundation and Arup, a consultancy, published a list of 96 road schemes that the government's own officials had assessed as having high economic returns, but warned there was a £10.6bn shortfall in funding to build and finance them.
The benefit of many roads schemes is they are close to being ready for shovels in the ground, and so quick to create jobs. They also have a big impact on competitiveness by improving journey times and reducing unexpected delays for businesses transporting goods and their staff getting to and from work- benefits recognised in very good cost benefit return figures, said Stephen Glaister, the director of the RAC Foundation research organisation.
"It's not just Keynesianism spend money and create jobs, it would genuinely reduce the cost of business in this country," said Glaister, who has advised governments and is also emeritus professor of transport and infrastructure at Imperial College London.
