Highways England has been warned it will face a backlash if an upgrade to the A47 is among 16 road schemes which are under review.

The government's value-for-money watchdog the National Audit Office revealed in a recent report that 16 of 112 major projects are being 'reconsidered' to make sure they are 'deliverable and affordable'. Highways England - the road building body - will not say which of the schemes are at risk.

MPs, who met Highways England bosses last month, remain optimistic that an upgrade to six parts of the A47, will go ahead. The plans include the dualling between Blofield and North Burlingham and Easton and North Tuddenham.

An initial consultation was launched last month.

North-West Norfolk MP Sir Henry Bellingham said roads minister John Hayes was set to visit the A47 in King's Lynn on May 11. He thought it was unlikely an official would have approved the visit if there was going to be bad news.

'It would be most unwise to do that [curtail the scheme] because of all the hopes that have been built up, not least by David Cameron [the former prime minister] and the promises he made before the last election, the continuous lobbying from MPs and the positive responses from ministers.

'They would hit a tidal wave of a backlash if they did try to alter the scheme by downgrading or removing any schemes from the programme,' he said. The long-serving Norfolk MP also said that the six current schemes were the minimum acceptable. 'It is not exactly earth shattering, but it is important and a move in the right direction.' Broadland MP Keith Simpson, who was also at the meeting with Highways bosses a few weeks ago, said they were being 'crab like' and 'talking about the slow progress' at a meeting a few weeks ago. 'I am sure that if there is any doubt we will lobby very heavily indeed,' he said.

The National Audit Office said they had been told schemes were being 'reconsidered' to make sure they were 'deliverable and affordable'. The NAO claimed problems had been created by drawing up plans in just 17 months so they could be announced before the 2015 general election.

Rail planning usually takes 30 months.