The combined majority opposition in the House of Commons says it's time for an emergency debate on the future of the Canadian Wheat Board.

Agriculture critics from the Liberals, N-D-P and Bloc Quebecois say the minority Conservative government is moving to cripple the wheat board.

They want the Commons agriculture committee to hold emergency hearings next week to hear from wheat board advocates who they say are being muzzled by the government.

Stephen Harper's Conservatives are aggressively pursuing an election promise to make participation in the wheat board voluntary for western farmers.