Adam GrettonA decision on the full dualling of the A11 will not be made until after the general election on May 6, it has emerged.Adam Gretton

A decision on the full dualling of the A11 will not be made until after the general election on May 6, it has emerged.

Ministers were urged to 'get on and dual it' when a public inquiry into the upgrade of the road between Thetford and Barton Mills came to an end in January.

But campaigners spoke of their frustration after having to wait until the outcome of the general election - called by Gordon Brown yesterday - for a decision on the multi-million pound project.

Leading politicians and business leaders had hoped that the nine-mile road widening scheme could be rubberstamped before the race for 10 Downing Street began.

Now the final leg of the A11 upgrade could be overseen by a different minister after transport secretary Lord Adonis ran out of time to back the project. The secretary of state has yet to receive the report of planning inspector Neil Taylor, who oversaw the A11 public inquiry, which came to a close nine weeks ago.

The inspector's findings are due to be sent to the government later this month , but not in time to be passed before parliament is officially dissolved on Monday .

Charles Clarke, Norwich South MP, said he was still hopeful that the Highways Agency works could start as timetabled at the end of the year.

'I am extremely disappointed that the planning inspector's decision has taken so long and has not reached the secretary of state by this time. I will continue campaigning for this and hope the new government after May 6, whatever party, will complete this process because it is so important to the Norfolk economy. I am sure this will be an election issue and Labour is committed to the dualling,' he said.

The project, which would cost between �106m and �147m, is estimated to be worth almost �600m to the Norfolk economy and would improve safety, capacity, and journey times along the A11, as well as improving the quality of life for people living in Elveden.

A fully dualled road between Norwich and London was first raised by Edward Heath's Conservative government almost 40 years ago and is scheduled for an autumn 2010 start date, if approved by whoever is transport secretary after the election.

Elizabeth Truss, Conservative parliamentary candidate for South West Norfolk, yesterday accused Labour of being 'too slow' in delivering the project.

'It is a huge shame that Labour failed in their 13 years in power to approve this. The A11 is extremely high on my agenda as local candidate. It is very important for the economic development for the area and I will be fighting that it is on the list of projects that retain funding,' she said.

Daniel Cox, leader of Norfolk County Council, added: 'While it is disappointing the inspector's report on the A11 will now have to be considered by the incoming secretary of state, we will do whatever we can do ensure the crucial importance of the scheme to Norfolk people and the Norfolk economy, is brought to his or her attention as soon as possible.'

'The case for dualling the A11 has been accepted by the major parties and we will not rest until the scheme gets the final go ahead.'