President of the Catalan Government Carles Puigdemont (fourth from the left) and other members of the Catalan parliament applaud the results of the vote on a bill for a referendum on independence in Barcelona, on September 6, 2017 | Lluis Gene/AFP via Getty Images 7 takeaways from Catalonia’s insurrection day Catalan parliament approves October 1 independence vote.

MADRID — Catalan separatists moved from words to deeds Wednesday when the regional Cabinet of Carles Puigdemont signed a decree calling a self-determination referendum for October 1, and the secessionist majority of the Catalan legislative chamber approved a bill paving the way for the vote.

The move culminates a years-long build-up of the Catalan secessionist movement, which a decade ago barely gathered the support of 15 percent of Catalans, and places the regional government and the legislature in open defiance of Spain’s constitution and the conservative government of Prime Minister Mariano Rajoy.

The stage is set for one of the gravest political crises Spain has faced in its 40-year-long recent democratic history.

“Catalonia will decide its own future on October 1,” Puigdemont said in a speech after signing the decree. “No one has the authority nor the power to seize our right to decide.”

After approving the bill, secessionist legislators sang Els Segadors, the Catalan anthem. Pro-unity lawmakers had abandoned the hall in protest before the vote.

Rajoy’s Cabinet took the first legal steps to tackle the independence push before the vote took place by challenging in the Constitutional Court the decision by the bureau of the Catalan assembly to go ahead with the processing of the bill and by asking the tribunal to act against Carme Forcadell, the president of the Catalan chamber. The public prosecutor also announced a criminal action against the five lawmakers who made the decision, including Forcadell. Further legal action challenging the referendum law and Puigdemont’s decree calling the vote is expected Thursday.

“We’re going to defend the constitution, democracy and liberties,” Soraya Sáenz de Santamaría, the deputy prime minister, told reporters in the afternoon, adding the Catalan chamber’s session debating the bill was “embarrassing” and “a kick to democracy.”

Here are seven takeaways from Catalonia's insurrection day.

1. There may not be a vote

Madrid and the Spanish judiciary have enough tools to prevent a vote, which will most likely be declared unconstitutional by the courts. Rajoy gave a hint Wednesday on how he intends to proceed: challenging all legal steps in the courts and targeting the top officials involved. The Constitutional Court has powers to urge officials to comply with its judicial decisions and suspend them from office if they refuse to do so. Other measures could include the seizure of some competencies of the regional executive.

Rajoy is under increasing pressure from some conservatives to teach Catalan separatists a lesson, but a harsh response could lead to increased support for independence in Catalonia. Madrid may opt for a softer approach, avoiding the most drastic measures and tolerating a de facto vote — similar to the informal ballot on independence that took place in 2014 — while refusing to accept its legitimacy and ignoring its results.

2. Puigdemont in the firing line

Whatever the outcome, Madrid and the Spanish courts are determined to make Catalan officials pay for challenging the country's unity.

While Puigdemont has vowed to go to prison for the sake of independence if necessary, Catalan officials are more likely to face being banned from public office and fines. That was the case for former Catalan President Artur Mas and those responsible for organizing the 2014 informal vote on secession, who were found guilty of disobeying court orders.

Spain's Court of Auditors on Tuesday hinted what’s to come for Puigdemont and his allies when it demanded Mas and other organizers of the 2014 vote post a €5.1 million bail for the public funds used in organizing the 2014 ballot.

3. A common unionist front emerges

The leader of the main opposition Socialists, Pedro Sánchez, and the head of the liberal Ciudadanos party, Albert Rivera, have publicly offered their support to Rajoy in order to maintain the rule of law in the face of the Catalan challenge. Together with the PM’s Popular Party, the common unionist front adds up to around 73 percent of lawmakers in the Spanish parliament and 39 percent of the seats in the Catalan regional chamber. Rajoy, Sánchez and Rivera exchanged calls this week and plan to meet Thursday.

Whereas Rajoy’s minority government can count on the support of a majority of the opposition, slight differences have surfaced in how each party wants to tackle the issue. Rivera, for instance, asked Rajoy not to tolerate another informal vote on independence like the one in 2014. Sánchez, on the other hand, said Wednesday in a radio interview the issue shouldn’t be over dramatized.

“They call it a referendum but it’s not a referendum,” Sánchez said.

4. Propaganda is key

Both sides are waging a merciless propaganda war in which facts are systematically spun, no topic is off-limits — not even the terrorist attacks in Barcelona and Cambrils last month — and those who attempt to stay on the fence are publicly shamed.

At stake is how to portray the whole conflict at the Catalan, Spanish and international level. Pro-independence forces say Spain is an authoritarian country that refuses to allow Catalans to express their democratic will at the ballot box. The Spanish government labels separatists fanatics who despise democracy and the rule of law.

While the Catalan government has sought and failed to obtain meaningful backing from foreign governments, it has proven skilful at making its voice heard in the foreign media. The public relations war is only likely to increase in the run up to October 1, with both sides attempting to pin the blame on the other.

5. A Catalan Maidan could backfire

One of the most delicate matters is whether the current conflict could escalate to a civil disobedience campaign in the streets of Catalonia, mirroring the 2014 Ukrainian revolution.

“If there was a government offensive to remove the ballot boxes, then obviously we will mobilize the citizens to prevent that from happening,” Marta Rovira, the No. 2 of the Catalan Republican Left — Puigdemont’s coalition partner — told reporters Sunday.

Such a move would obviously attract international attention, fulfilling one of the aims of Puigdemont and his allies, but it may be a double-edged sword that could backfire against the separatists.

Some independence supporters have long advocated for civil disobedience — namely the radical-left Popular Unity Candidacy, the junior partner of the secessionist alliance. A significant portion of independence supporters, however, are middle-class moderates, who may be reluctant to join such actions or even drop support for the cause if things get out of control.

Much attention will be paid on Monday to the Diada, or Catalan national day, a celebration when millions have rallied in support of independence in previous years, for hints of how the conflict may play out in the streets.

6. It's a numbers game

If the referendum does go ahead, much will depend on how many people actually vote. Catalan unionists are largely expected to abstain. Pro-independence forces have vowed the referendum will be binding regardless of turnout, but it’s clear low participation would weaken their leverage.

Support for Catalan independence has fallen in recent polls from a peak in 2013. Madrid was optimistic the country's current economic revival could reduce the movement to a more manageable level — the economic crisis was one of the key drivers of the Catalan independence push. Any misstep in the current crisis could blow up the equation.

The latest research from the Catalan government-funded Centre d'Estudis d'Opinió found 48 percent of citizens wanted a referendum regardless of the opposition of the Spanish government, while 23.4 percent wanted a vote only with a green light from Madrid. In the same poll, 41.1 percent supported secession, while 49.4 percent opposed.

7. The headache won't end October 1

Whether the vote takes place on October 1 or not, the day after will prove problematic for Spain. The Catalan government and the secessionist majority of the regional chamber have rebelled against the principle of Spanish national sovereignty, upheld by the country’s constitution and supported by a majority of Spanish political forces. A significant compromise would be needed for both sides to find a negotiated solution.

Puigdemont told POLITICO in July a proposal without independence, which secures Catalan competencies and addresses complaints about language, finances, infrastructure and education, would obtain widespread support in Catalonia.

The Socialists' Sánchez proposed a commission in Congress to explore potential solutions and has obtained Rajoy’s backing for the initiative — but significantly not the support of Catalan independence forces. Even if it gets going, such a commission will have to overcome massive political difference both between pro- and anti-independence supporters and among the forces defending the unity of the country.