Norfolk MPs are to press the government to fast-track the completion of A11 dualling so that work will start in the current financial year.

They have been encouraged to do so by an announcement from deputy prime minister Nick Clegg that Whitehall is to be made to 'put its foot on the accelerator' with key infrastructure projects that are 'the ones most important to growth', and that 40 of them will be given 'new special priority status'. The scheme to dual the remaining single-carriageway stretch of the A11 between Thetford and Barton Mills is 'one of the most obvious projects to be brought forward', SW Norfolk Tory MP Elizabeth Truss told the EDP yesterday. It had a very high benefit-cost ratio, she emphasised, and would promote growth in Norfolk and Suffolk, and beyond.

Work on the dualling, which survived the government's spending axe last autumn, is set to begin in 2012-13, and the prime minister confirmed that on his recent visit to Norwich.

But Ms Truss is to write to treasury chief secretary Danny Alexander to ask that the scheme be included in the list of accelerated schemes and brought forward into the present financial year. The Liberal Democrat minister, the number two at the treasury, is co-ordinating the fast-track operation, and also announced on Sunday that �500m is to be found from underspent budgets and treasury reserves to revive stalled infrastructure schemes.

North Norfolk Lib Dem MP Norman Lamb said he wished to join with Ms Truss in urging Mr Alexander to put the A11 on a list of accelerated projects. There had been 'an intense focus' at the Lib Dem conference, he said, on 'increasing our attempts to promote growth by infrastructure projects such as that A11 which are in a state of readiness'.

'It makes enormous sense and it is up to local MPs to make the case', he continued. Simon Wright, the Lib Dem MP for Norwich South said he would also be raising the issue with Mr Alexander.

A key player in an attempt to get the scheme brought forward could be the West Suffolk Tory MP Matt Hancock, who is politically close to chancellor George Osborne, for whom he used to work as an aide. 'The sooner work starts on the A11, the better it will be', he said last night.

The chances of getting the scheme fast-tracked may have been increased by yesterday's gloomy report from the International Monetary Fund predicting that the British economy will grow by only 1.1pc this year - well below the government's latest forecast of 1.7pc expansion.

Government sources were pointing out last night that the A11 scheme has to go through statutory procedures and that it might not be possible for that reason to bring it forward into the present financial year. But Norfolk and Suffolk MPs can be expected to counter that the very point of fast-tracking is to cut through set timetables.

Mr Clegg stated last week that 'we're going through the nation's capital spending plans to hand-pick up to 40 of the biggest infrastructure projects, the ones most important to growth, which will be given new special priority status'.

Each would be rigorously examined by ministers 'to make sure there are no delays, no blockages and the economy feels the benefits as quickly as possible' he said.

'Where we need to get investors and developers in, we'll do so. Where local conversations need to happen, we'll make them happen. Whatever the problem is – regulation, funding, procurement, planning - if we can help unblock it, we will.'

The bid to speed up dualling of the A11 has also been welcomed by a business leader and a senior member of Norfolk County Council.

Graham Plant, cabinet member for planning and transportatation at the county council, said: 'An early start for the A11 would be a shot in the arm for the Norfolk economy. Over time, dualling this last stretch of the A11 would be worth more than �600m, but bringing forward the start date would be an immediate boost for business confidence.'

Andy Wood, chairman of the New Anglia Local Enterprise Partnership, added: 'We have been pressing for the dualling of the final stretch of the A11 for a long time. We were pleased when David Cameron came to Norfolk and said he supported it and delighted when it was included in the budget.

'We are eager to see work start as soon as physically possible.'