NATIONAL park chiefs have come out against plans to build a dual carriageway through ancient woodland.

Last month Highways England proposed six colour-coded routes for the A27 Arundel Bypass in a bid to ease traffic on the road.

But now Margaret Paren, chairwoman of the South Downs National Park Authority, has said every option would “impact negatively” on the park.

“The Authority urges Highways England to address the shared concerns regarding severance of this sensitive landscape, cultural heritage and its biodiversity,” she said.

The authority, which controls planning across the Downs, came out against the proposals after a meeting in Midhurst on Tuesday.

Outside the meeting, members of the South Coast Alliance for Transport and Environment protested against the “damaging” bypass.

Chairwoman Henri Brocklebank said the plans were “taking a sledgehammer to crack a nut”.

She said: “All will cause significant damage while less damaging alternatives haven’t been fully considered.

“We deserve something better than this.”

The six options range from a three-mile bypass between Crossbush and the west of Arundel to a new five-mile dual carriageway featuring a bridge in Binsted village.

The Sussex Wildlife Trust has also come out against all six options.

Conservation officer Jess Price said the bypass plans would “destroy and isolate precious habitats”.

She said: “This complex and wonderful interconnected ecosystem is home to rare and protected wildlife including 14 species of bat.

“All six options will significantly and permanently sever our natural environment, having an outrageous impact on wildlife and the landscape.”

Ms Price also expressed concerns over financing.

She said: “A budget of between £100 and £250 million has been allocated to the scheme, but only two of the six options fall within this budget.

“Even £250 million is too much public money to spend isolating and destroying habitats during a climate and ecological emergency.”

A Highways England spokesman said the authority members had “a range of valid and genuinely held views”.

But he said a bypass would address congestion on the road.