His comments will come as a blow to UK ministers who have been promising that a newly elected Mrs Merkel could break the current Brexit deadlock. “The FDP are likely to be in the coalition, and they will not allow Mrs Merkel to ignore German industry,” one senior government minister recently told the Daily Telegraph.

Mr Theurer’s comments on the limited “room to manoeuvre” echo the German government’s private line to ministers and the warnings of senior figures in Mrs Merkel’s Christian Democrat (CDU) party.

A senior aide to Mrs Merkel told the Daily Telegraph that German Brexit policy would be the “same old soup” after the election, while a senior CDU politician with links to Mrs Merkel - who asked to remain nameless because of the on-going election campaign - was equally vehement.