The full closure of Bath's Cleveland Bridge for urgent repairs is "increasingly unlikely" to start this month after a worker tested positive for Covid.

Councillor Manda Rigby said it was not yet clear how many other people working on the £3.8m project would have to self-isolate.

The Grade II*-listed bridge was due to close to traffic for at least three months on June 28, a date that had already been pushed back following closer inspections of the structure.

After talks with Wiltshire Council broke down, traffic is set to be diverted through South Gloucestershire, but councillors said drivers will use the A350 regardless.

Cllr Rigby told a webinar on the works on June 17: "June 28 is looking increasingly unlikely, because we aren't through the pandemic yet.

"One of the workers has tested positive for Covid and was in contact with quite a lot of the other workers on the bridge.

"In terms of health and safety, we have to work with the contractors to see how many people are going to have to self-isolate and what impact it will have on our plans to close the bridge on June 28.

"I wish I could give a definitive answer and say it's going to close on X date, it's going to take X number of weeks, and we're going to take the scaffolding down for another six weeks and that will be it, but please bear with us.

"We have to do this as safely, effectively and efficiently as we can."

The nearly 200-year-old bridge was reinforced in 1928 and repaired in the 1990s, when engineers said it was safe to carry vehicles weighing up to 18 tonnes.

Bath and North East Somerset Council has tried to set that as a permanent weight limit but faced opposition from Wiltshire and was shot down by central government because the bridge forms part of the strategic road network and carries 17,000 vehicles a day.

A temporary 18-tonne limit was introduced ahead of the repairs but continues to be breached. It will remain open to pedestrians, cyclists and emergency vehicles throughout the works.

Cllr Rigby said: "We can't have 44-tonne vehicles going over. The heavier and more vehicles we have that go over, the sooner we'll be in this position again – we'll be having these same arguments in 10 or 15 years.

"A fair sharing out of traffic from the M4 to the south coast must be in everyone's interest so we aren't putting all our traffic through South Gloucestershire and Wiltshire when the bridge is closed."

Council leader Kevin Guy said the weight limit had been "used as a political football" ahead of the recent elections in Wiltshire but satnavs will take drivers along the A350 through the county regardless of the recommended diversion, so it would be fairer on residents to have proper signs in place.

"I can sympathise with Wiltshire councillors and MPs – HGVs shouldn't be going through the centre of Westbury as much as they shouldn't be going through the centre of Bath," he said.

"I will do everything in my power to try to limit the number of HGVs coming over Cleveland Bridge. I can't guarantee that any actions B&NES Council takes won't be overruled by the secretary of state."

The government is currently trying to find the best north-south route. It will lead the discussions through the Western Gateway, a group of eight councils including B&NES Council and the West of England Combined Authority.

Bath MP Wera Hobhouse said: "The government position is we need to find agreement with Wiltshire. I really want to work constructively to find a solution rather than having a standoff which isn't good for anybody."

She said the government would not have given £3.5million to fund the repairs if they were not necessary, adding: "It's in nobody's interest that the bridge falls into the river.

"The responsibility for our beautiful heritage is not just for us in Bath but the surrounding areas. The strategic route through Bath isn't the best route."