71 separatist MPs in the Catalan Parliament, from the governing Junts Pel Sí ("Together For Yes") coalition and the radical-left CUP, voted to pass a bill that outlines plans for secession from Spain at 12:50 a.m. on Friday morning.

There were 10 abstentions from the Podemos coalition. Opposition groups (Popular Party, Socialist Party, Ciudadanos) walked out when the Speaker announced the vote, after two hours of debate and several more of procedural matters in the chamber.

Jordi Orobitg, speaking for Junts Pel Sí during the debate, said that thanks to the bill—officially titled the "Legal Transition & Foundational Law Of the [Catalan] Republic"—Catalans could now know what to expect.

"Catalonia will be what Catalans want it to be", he said.

The secession bill references a clause in the referendum bill (passed yesterday) that says it will only come into effect if the "yes" vote wins on October 1. If it does, separatists want to declare independence from Spain within 48 hours.

Xavier García Albiol, speaking for the Popular Party in Catalonia, said that separatists "know they are not going to break Spain: they do not have social support, international consideration or legal reason".

Inés Arrimadas (Ciudadanos) said secessionist forces had "blown up all your ships, burnt all your bridges", adding that "40 years of prosperity are at stake".

Ms. Arrimadas said she thought the social tensions created in Catalonia by the referendum and secession process would take "years" to fix.

Miquel Iceta, the leader of the Catalan Socialist Party, said "this law will end up straight in the legislative bin" and that separatists sought to go down in history "as a footnote".

"You know the referendum you have promised cannot happen and that there will be no republic on October 2".

Joan Coscubiela, speaking for the Podemos coalition, said separatists had used up all of their political credibility in "48 hours of darkness" and "handed the flag of democracy to the Popular Party".

Bernat Salellas, for the radical-left pro-independence CUP, argued that "sovereignty is the ability to legislate on everything we want to" and that "with this law we are trying to build a legal instrument as we understand the law, from a pluralistic vision".

Earlier in the evening, Catalan First Minister Carles Puigdemont, referring to an announcement by the Director of Public Prosecutions that Spain would file criminal charges against separatist leaders, told a TV channel that "faced with a tsunami of criminal charges, there will be a tsunami of democracy".

Catalan government spokesman Jordi Turull said in a statement on Thursday afternoon that a "concealed state of siege" now existed in the region.

Spanish Prime Minsiter Mariano Rajoy said that the "illegal" Catalan referendum would not happen and that the Spanish state would act "to defend democracy".