Two residents of the Norfolk Broads area have won permission to take the Environment Agency (EA) to judicial review over water abstraction, it has been reported.
The BBC has reported that the EA set out plans last year to review this in parts of the Broads, which is a national park.
Tim and Angelika Harris, who own part of Catfield Fen in the area, want the EA to include a wider area in its review of abstraction licences in the Ant Valley to include neighbouring sites such as Hickling Broad and Smallburgh Fen.
They said water abstraction is causing irreversible damage to habitats in the area including to rare orchids and swallowtail butterflies.
The couple are understood to have spent £1m on legal costs and conservation measures to protect these wetlands.
Penny Simpson, a lawyer acting for Mr and Mrs Harris, told the BBC their legal battle was significant: "It definitely could be a landmark case because it's shining a light on the extent to which public bodies such as the Environment Agency have to comply with duties that derive from European law.”
The EA said it was unable to comment due to the ongoing legal proceedings.