BARCELONA, Spain (AP) — The regional parliament of Catalonia in northeastern Spain has started debating a proposal by secessionist parties to set up a roadmap for independence from Spain by 2017.

The Barcelona-based chamber, where the secessionist parties hold a majority, will vote on the motion later Monday.

The initiative defies Spain's central government, which says it is unconstitutional.

Prime Minister Mariano Rajoy's government has pledged to take legal action against Catalonia's parliament if it approves the secession plan.

Catalan branches of Spain's ruling conservative Popular Party and the Socialist and the Citizens opposition parties filed appeals to halt the vote, but Spain's Constitutional Court ruled Thursday that it could go ahead.