Britain must designate its overseas territories as ‘bluebelt’ to help protect wildlife and prevent plastic pollution entering the oceans, campaigners have said.

Following the final episode of Blue Planet II which showed the devastating impact of humans on the world’s seas, the Great British Oceans coalition called on the government to safeguard its remote marine zones, which are home to some of the world’s most endangered species.

Already 133 MPs have backed the campaign to create 1.5 million square miles of protected ‘bluebelt’ around seven British overseas territories which contain the breeding grounds for a quarter of the world’s penguins, and one third of the world’s albatrosses.

The proposed zone would cover Ascension Island, South Georgia, Saint Helena, Tristan da Cunha and the South Sandwich Islands, in the south Atlantic, as well as the British Antarctic Territory, the British Indian Ocean Territory and Pitcairn Islands in the southern Pacific. It would be the world’s biggest network of ocean sanctuaries.