Vince Cable yesterday revealed he was becoming increasingly baffled by the madness of his Tory allies, describing plans to toughen up strike rules as “simply potty.”

The Liberal Democrat Business Secretary said Conservative plans to change balloting laws to make it more difficult for workers to strike were “nonsense,” echoing unions’ cry of hypocrisy that MPs themselves would not be elected if they needed a 50 per cent turnout.

“I don’t think there’s any need for them. We have far fewer strikes than we had in the past and industrial relations are generally very good,” Mr Cable told BBC One’s Andrew Marr show.

“The particular proposal that they are making is that no strike should be valid unless over half of the union members have voted for it is simply potty.

“Most MPs wouldn’t be validly elected if that was the test. We’ve got police and crime commissioners with 15 per cent turnout.”