Beautiful as a rainforest' Brexit rules put chalk streams under threat

Walk along the gin-clear River Itchen in Hampshire and you might see otters, salmon, kingfishers and clouds of mayflies, all supported by the unique ecosystem of the chalk stream.

- Helena Horton

We do not have tropical rainforests and tigers or elephants in Britain; our wildlife is arguably more modest in appearance. But our chalk streams are some of the rarest habitats in the world - there are only 200, and England boasts 85% of them. If you look properly, they are as biodiverse and beautiful as any rainforest.

Despite the rarity and importance of these very pure rivers, which are full of minerals from the chalk aquifer, they have no specific legal protections.

Environmentalists fear the Labour party's planning bill will use the country's departure from the EU to make it legal for developers to destroy them, as long as they offset the damage by paying into a fund to create nature somewhere else.

"Chalk streams are an irreplaceable habitat. They are incredibly fragile and incredibly rare, but we suck up our drinking water from them and dump our sewage in them," Debbie Tann, chief executive of the Hampshire Wildlife Trust said. "I think the levy is almost designed to create a replacement or an alternative habitat somewhere else for the thing that you're impacting. That isn't going to work in a chalk stream context. You can't just create a new one somewhere else."