The ban on fishing bluefin tuna should not be lifted after Brexit, scientists have said, despite growing pressure from anglers.

It is currently illegal to catch the enormous variety of tuna that can grow to 2,000lbs and which largely vanished from British waters in the 1990s because of overfishing.

However in the past few years large schools of the bluefins have been spotted off the south coast of England and in the Irish sea, leading to calls for the ban to be lifted.

Anglers claim Brexit presents a ‘unique opportunity’ to relax fishing laws, but scientists say the resurgence of the fish is down to a natural phenomenon of sea warming rather than the recovery of the species.

A new study by British marine biologist Dr Richard Kirby, formerly of Plymouth University, and the University of Lille, found the fish are coming further northward because of the Atlantic Multidecadal Oscillation (AMO) which increases sea temperatures in a 60 - 120 year cycle.

"Bluefin tuna have been extensively overfished and the recent changes in distribution are most likely environmentally driven rather than due to fisheries management and stock recovery,” said Dr Kirby.

"Before we further exploit bluefin tuna either commercially or recreationally for sportfishing, we should consider whether it would be better to protect them by making the UK's seas a safe space for one of the ocean's most endangered top fish.”