A group of 30 British business people have written to the Prime Minister telling her to keep Britain in the single market and to take steps to avoid a rapid drop in migration after the UK leaves the European Union.

The founders of innocent drinks and Cobra beer, Richard Reed and Lord Bilimoria respectively, are both signatories to a letter urging Theresa May to keep Britain “open to trade and talent.”

Ms May is expected to give a speech in the near future on her plans Brexit, in which it is understood she will prioritise immigration over single market membership. Leading EU figures including Council President Donald Tusk and lead negotiator Michel Barnier have repeatedly stressed that full single market membership is not possible without free movement of labour.

In a letter to the Financial Times, Richard Reed, co-founder of Innocent Drinks, said: “There is no mandate for the kind of hard, destructive Brexit that will harm Britain’s enduring entrepreneurial spirit.”