A conservationist today warned, "Hands off the butterflies," as calls were made for more parking spaces at Shipley Station.

Susan Stead, of the Yorkshire branch of the Butterfly Conservation Society, spoke as transport bosses investigated ways of easing a parking crisis - including concreting-over part of a butterfly garden.

Bradford Passenger Consultative Committee chairman Councillor Ann Ozolins has asked train operator Arriva if the butterfly meadow can be reduced, stressing she does not want to lose it. But Mrs Stead said today: "There can be no compromise. The butterfly meadow cannot be viable if it is any smaller. It is not negotiable."

A Bradford Council official said the meadow was earmarked for conservation in the Unitary Development Plan - the blueprint for planning applications - and could not be used for parking without special reasons.

Arriva has been clamping down on illegal parking at the station but drivers say there are too few spaces and people are being discouraged from using trains.

The butterfly meadow was opened by naturalist David Bellamy in 1993 after species including the common blue, large skipper and small copper were found there.

Mrs Stead, a member of Bradford Urban Wildlife Group, said butterflies were thriving in their haven in the middle of the station. She said about 30 common blues had occupied it this year along with up to ten other species.

l On November 14, volunteers are welcome to help cut the meadow grass while the caterpillars hibernate.