The European Parliament’s fisheries committee said it would be “unacceptable” to give the UK’s seafood producers free access to EU markets if trawlers from the Continent “no longer had access” to British fishing grounds.

It recommended that the parliament agree that the two issues should be treated as a “single block” in the forthcoming Brexit negotiations, stating that one is “inseparable” from the other.

But Ian Duncan, a Scottish Conservative MEP, said this was “peculiar, unprecedented and counter-productive” as no other trade deal brokered by the EU has included access to fishing grounds as a requirement.

He wrote to Alain Cadec, the French MEP who chairs the committee, warning that the recommendation endangers the chances of the two sides striking a deal and pointing out this was not the basis of deals reached with Norway and Iceland.

Scotland’s fishermen reacted with fury, warning the MEPs that they would be told to “sling their hook” and arguing that the British seafood industry would instead sell its produce to China, India or Canada.