The A47/A11 Thickthorn roundabout revamp is under threat

The project to revamp the Thickthorn roundabout is one of several transport schemes which may be axed after Labour ministers said they had found a £22bn black hole in government finances.

Also under threat are plans to upgrade the Vauxhall Roundabout at Great Yarmouth.

The scheme at Thickthorn -  where the A47 meets the A11 on the edge of Norwich - has been in the pipeline for a decade but work has yet to start, following a long delay caused by a series of unsuccesful legal challenges from eco-activist Dr Andrew Boswell.

Under the plans - long considered one of the region's infrastructure priorities - a new sliproad off the northbound A11 will take motorists beneath both roads before re-joining the eastbound A47, eliminating the need to use the roundabout.

Norfolk County Council and the county's MPs consider the scheme vital to improve the safety of the junction, as well as ease congestion and provide an economic stimulus to the region.

Work has begun to dual two sections of the A47 in Norfolk (Image: Dan Grimmer)

The threat to it emerged at a meeting of the A47 Alliance, which is made up of councils and business leaders.

Jan Challis, from National Highways, the government company responsible for the road, told the group that the spending review meant all schemes where construction has not started were potentially at risk.

Chris Griffin, A47 programme lead at National Highways, added: "The scheme is part of the Department for Transport's review at this moment in time. I remain optimistic, but it is all dependent on the budget review."

Construction company Galliford Try had been due to do the work, but last summer, it emerged they would not be involved.

Mr Griffin said a new contractor had been chosen, but contracts were yet to be signed.

He said he hoped preparatory work at Thickthorn, pending the government pledging funding, would begin in December, with main construction starting next March.

Thickthorn roundaboutWHAT WOULD THE PROJECT INVOLVE?

As well as the new sliproad and tunnel, the changes would also see a segregated left-hand turn added for those travelling eastbound on the A47, a new footbridge and a fourth lane on the southern part of the junction.

The Thickthorn project, along with the Vauxhall one and the dualling of two sections of the A47, were among £300m of schemes announced by then prime minister David Cameron in 2014.

While dualling work - between Blofield and North Burlingham and from Easton to North Tuddenham - finally began this summer, work at Thickthorn and Vauxhall roundabout has yet to start following a string of delays.

In 2021, Graham Plant, then deputy leader of Norfolk County Council, said five years had been wasted because National Highways was moving so slowly at starting work.

The Vauxhall Roundabout at Great Yarmouth (Image: Archant)

Later, Dr Boswell's legal challenge prevented National Highways from doing all but preparatory work.

Dr Boswell had taken his argument - that the government acted unlawfully in approving the schemes because it did not properly consider the cumulative environmental impacts - to the High Court and the Court of Appeal.

The former Green city and county councillor hoped the Supreme Court - the highest court in the land - would also hear his case, but that was rejected in May.

That exhausted his legal avenues and meant National Highways - which said his challenges delayed work by 20 months and added tens of millions of pounds to costs - could finally start the schemes.

But without a contract signed on the Thickthorn scheme it is vulnerable to the government's axe.

Transport secretary Louise Haigh (Image: James Manning / Press Association)

WHAT IS THE SPENDING REVIEW?

That review was triggered after the new Labour government said it inherited £2.9bn of unfunded schemes from the Conservatives and might need to cancel some.

Transport secretary Louise Haigh announced the "internal review" of the Department for Transport's spending portfolio in July.

She said: "We will bring in external expertise and move quickly to make recommendations about current and future schemes.

"Communities up and down the country have been given hope for new transport infrastructure, with no plans or funds to deliver them. This government will not make that mistake.

The fate of the schemes will become clearer after next month's autumn budget.

Dr Andrew Boswell challenged the A47 scheme decisions in court (Image: Dan Grimmer)