A decision over the multi-million pound revamp of one of Norfolk's busiest junctions is due to be made this week - but it could then end up being challenged in the High Court.
An environmental campaigner, who has already launched legal challenges over the dualling of two sections of the A47 in Norfolk, has said he intends to do likewise over the Thickthorn junction changes, if it gets permission.
Newly-appointed transport secretary Anne-Marie Trevelyan is due to decide whether to grant National Highways development consent for the £50m to £100m scheme by Friday, October 14.
The plans include a new slip road off the A11 northbound, which will take motorists beneath both roads before re-joining traffic on the A47 heading towards Great Yarmouth - eliminating the need to use the Thickthorn roundabout.
The changes would also see a segregated left-hand turn added to those travelling eastbound on the A47, a new footbridge and a fourth lane on the southern part of the junction.
What planning inspector Matthew Shrigley has recommended for the scheme will not be known until Mrs Trevelyan makes her decision.
She could choose to agree with Mr Shrigley's recommendation, or could go against his recommendation - as happened with the rejected plans for Anglia Square in Norwich two years ago.
If permission is granted, National Highways had hoped to start work early next year.
Two other A47 schemes - the dualling of 1.6 miles of the road between Blofield and North Burlingham and five-and-a-half miles of road between Easton and North Tuddenham - have been granted consent in recent months.
However, both those schemes could end up before judges in the High Court, if environmentalist Andrew Boswell's legal challenges to them lead to judicial reviews.
And Dr Boswell has said he intends to challenge the Thickthorn decision too, if it does get the go-ahead.
Dr Boswell, a former Green Party city and county councillor, said: "National Highways almost salami-sliced the scheme as it could consider environmental impacts for each individual section - and not the overall impact, which it should have done.
"The legal grounds we will lay will be the same as the other two challenges - that an accumulative assessment has not been done."
The decision on Thickthorn had been due in September, but was put on hold following the death of the Queen.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here