From left to right: Former President of the Catalan National Assembly Carme Forcadell, President of Catalonia Artur Mas, Junts pel Si leader Raul Romeva and Esquerra Republicana de Catalunya leader Oriol Junqueras celebrate their election victory | Alex Caparros/Getty Images Catalan parliament votes to break with Spain Pro-independence parties obtained a majority of seats in September’s regional election.

The Catalan regional parliament adopted Monday a 9-point resolution declaring the official beginning of separation from Spain, despite the adamant opposition of Spanish Prime Minister Mariano Rajoy and the Constitutional Court.

Following a heated-up debate, 72 of the 135 representatives voted for the bid, with 63 votes against.

The independence plan, initiated by Catalan regional President Artur Mas, demands a “massive, sustainable and peaceful” secession from Spain, that must empower “citizens at all levels” and “is not subject to decisions of the institutions in Spain, including the Constitutional Court.”

Spain's Constitutional Court ruled last year that a planned referendum on independence was unlawful; It went ahead anyway, as a non-binding vote, and about 80 percent of voters said they wanted to break with Spain.

Raül Romeva, head of the pro-independence party Junts pel Sí (Together for Yes), said the declaration follows a “clear demand” of the Catalan people.

In Catalan regional elections on September 27, Junts pel Sí and the far-left Candidatura d'Unitat Popular (CUP), which is also in favor of independence, achieved a majority in terms of seats, but short of a majority in terms of their percentage share of the vote, which came in at 47.8 percent.

Proponents of separation from Spain argue that as well as the two pro-independence parties who voted for secession in September, a third group — the left-wing Catalunya Sí que es Pot (Catalonia Yes We Can) — did not take a clear stand on the issue. Taking out their ‘neutral’ vote of 8.94 percent, a majority of the votes would have gone to the pro-independence camp.

“No matter how you count, in votes or in seats, the result of the elections expresses a clear will,” Romeva said.

MPs from the center-right Ciudadanos party, Rajoy's conservative Popular Party and the main opposition Socialist Worker’s Party lashed out at the declaration.

“This is a provocation of democracy ... and scorns the millions of Spanish people who fought for it,” said Inés Arrimadas of Ciudadanos. “We need to reform Spain, not break it.”

The independence movement is shaking Spanish politics just weeks before national elections to be held on December 20. Rajoy said last month that as long as he is in power, “I will guarantee that what is written in this resolution will not enter into force.”

A new term for Mas as Catalan president will also be submitted to MPs Monday afternoon, in what is expected to be a much closer vote.