Seals, dolphins, whales and rare birds have been put at risk by a local council which filled a cliff with plastic foam which was destroyed by rain and blown into the sea, environmental groups have said.

Hilbre Island, between England and Wales, is known by wildlife-lovers to be the perfect place to spot endangered species and a much-loved grey seal colony.

However, visitors and those who volunteer to keep the area clean were shocked to find plastic foam strewn under the cliffs, in easy reach of wildlife, and swept into the sea during the bad weather over the weekend.

Emily Baxter, the senior marine conservation officer for the North West Wildlife Trust told The Telegraph: "The use of plastics in coastal environments is not appropriate. We do get a lot of storms and bad weather in this area so that would be to be expected, and we certainly shouldn't be doing anything that's going to increase the plastic pollution in our seas.

"The Dee estuary is really important for a huge number of wading birds and the invertebrates they feed on."