Tory plans to make it more difficult for workers to strike are "simply potty", Vince Cable has said.
The Business Secretary described as "nonsense" Conservative plans to change balloting laws so that a threshold would have to be reached before a strike could be held.
The proposal is to only allow strikes when half of a union's members have voted in the ballot for it but most MPs would not pass that test, Mr Cable said.
He spoke after a million public sector workers took industrial action demanding fairer pay and pensions and a slowdown in job and spending cuts this week.
Mr Cable told BBC One's Andrew Marr Show: "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.
"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% turnout.
"I think the proposal is nonsense."