Weeks of disruption on main roads through Chippenham are expected when an underground cable is laid to connect Castle Combe Circuit with a Chippenham substation.

Roads to be dug up include Langley Road, which was resurfaced just last year, Park Lane and Bristol Road, including the Bumpers Farm roundabout.

More than 2,700 metres of high voltage grid connection cables need to be laid underground to accommodate a solar farm planned for the racing circuit, for which Sunsave 17 (Castle Combe) Limited was awarded planning permission last month.

Debbie Marriage, senior planning consultant on behalf of Sunsave 17, said there was not a substation closer.

The work involves digging trenches half a metre wide and up to 1.5 metres deep, with about 100-200 metres of trenching done on a typical day.

She said: “The work will last a few weeks. It’s not timetabled yet but will be over the next few months. It is being undertaken with full co-operation from Wiltshire Highways Authority.”

Planning consent is currently being sought to lay the cable through a farmer’s field rather than disrupting Yatton Keynell. But the onward route proposed is between the A420 and Cocklebury Lane, up to the substation near the railway line.

Residents and motorists faced three months of disruption on Langley Road last spring when the potholed road was resurfaced between the New Road roundabout and the junction with Hill Corner Road.

Wiltshire councillor for Monkton, Chris Caswill, said: “It’s quite a shock. I’m keen on renewable energy but they didn’t make any mention of digging up roads in their application.

“I find it extraordinary that a decision taken about a planning application that is going to have a huge impact on traffic flows, road surfaces and lives of residents in Chippenham, can go forward without anybody, even local representatives, being asked their views.”

Philip Scott, manager of Hale Veterinary Group in Chippenham, said he was not looking forward to more disruption again, but recognised it had to be done.

“We’ll have a few weeks of absolute misery,” he said. “It was difficult for clients and vets to get in and out and potentially there’ll be congestion if it’s a single lane, although it depends on the traffic. But it’ll have to be done unfortunately.”

Wiltshire Council said the solar farm applicant would be responsible for resurfacing after trenches are dug and would be obliged to do it to a high standard.