The MP for Chesham and Amersham has called for ‘precious’ chalk streams such as the River Chess to be given special designation.

Sarah Green argued that the globally rare habitats, which are a key feature of the Chilterns landscape, should be protected from pollution and other activities by water companies.

She said: “What is needed is a recognised special status, a special designation for chalk streams so that they can get the protection that they actually need.”

The MP made the comments during a Westminster Hall debate on tackling sewage discharges by water firms in chalk streams, which support animals such as water vole and brown trout.

Her call to give chalk streams greater protection came after the Environment Agency announced that it had asked Affinity Water to resume water abstraction in the Chess – although it has since rowed back on the plans.

During the meeting, Green requested a national chalk streams strategy as she addressed Emma Hardy, the parliamentary under-secretary of state at the Department for Environment, Food and Rural Affairs.

Green added: “What is missing is a strategy across the country for all chalk streams, which is why I am calling on her in her position as a minister to give the chalk streams the designation and special status, they need so that it is not treated in this piecemeal way.”

Hardy said chalk streams were under ‘stress’ and said the government was working to conserve the rare waterways, including by improving wastewater treatment works.