Nine Catalan politicians jailed for their part in a failed 2017 independence bid are set to be pardoned.

Spain's Prime Minister Pedro Sanchez said he would ignore protests from opposition parties and approve the move on Tuesday at a weekly meeting of his cabinet.

He hopes the gesture will open the door to a broader rapprochement with the semi-autonomous region.

"Confrontation didn't serve to solve any problem," Sanchez said in a speech at Barcelona's opera house.

"To reach an agreement, someone must make the first step," he said. "The Spanish government will make that first step now."

Opinion polls suggest most Spaniards oppose the pardons.