A commuter car park in Essex is to be one of the first test cases of whether the government will enforce new legislation aimed at protecting national parks and landscapes in England.

Dedham Vale is a designated “national landscape” on the border of Essex and Suffolk, home to increasingly rare species including hazel dormice and hedgehogs. Within it is Manningtree station, where the train operator Greater Anglia built an extension to the car park to cope with increased traffic.

Campaigners say the 200-metre long wall and a bike shed built as part of the extension inhibits public access to St Edmund Way, an ancient pilgrimage path, generates light pollution and threatens habitats. They are now locked in dispute with the planning inspectorate over whether the development should be allowed to stay and have applied for a judicial review, which is likely to be heard early next year.