A churning crisis in Spain looks set to reach yet another turning point this weekend, as the cabinet gathers to decide the government’s response to Catalonia’s push for independence.

Ministers are expected to set the wheels in motion to suspend the autonomy of the wealthy northeastern region, a move not undertaken in the country’s last 42 years of modern democracy.

What’s the latest? On Saturday, the government of Prime Minister Mariano Rajoy began holding an extraordinary cabinet meeting to decide the measures that may be taken the next few weeks to enact Article 155 of the federal constitution against Catalonia.

The move comes after an unauthorized referendum on secession held in the region on Oct. 1. That resulted, in addition to clashes between police and voters, in a strong majority for independence from Spain. After days of back-and-forth over the matter, Catalan President Carles Puigdemont refused to heed the government’s warning to back down by Thursday, prompting Rajoy to call the special meeting of ministers.

Article 155 gives the government power to strip powers of autonomy from a region and to take control itself, if certain conditions are met.

If that “nuclear option” is triggered, the consequences could include the dismissal of the Catalan government and new regional elections. On Friday, Spain’s main opposition party, the Socialists, said they would support a move by the ruling Popular Party to hold new elections in Catalonia, according to Reuters and other media outlets.

What is the intent of Article 155? Just two paragraphs in Spain’s 1978 constitution, the article basically gives the central government the necessary powers to take over a region.

Article 155 is referred to as the “nuclear option” because of its last-ditch nature and politically explosive potential. The provision was put in place as the country made its transition from Franco’s dictatorship to democracy. It aimed to help maintain a power balance between the central government in Madrid and its 17 different regions, including Catalonia — “Catalunya,” in the local language

The article simply states that if an autonomous region acts in a manner that has “gravely attacked the general interest of Spain,” the government could adopt measures needed to force the region to comply.

But the government must win approval in the Senate to put such measures in motion, and Rajoy’s party holds a slim majority in that chamber. A vote on the matter could take place as early as Saturday, it is believed.

What happens next? If the central government gets approval, that doesn’t mean a takeover of Catalonia would immediate, noted Antonio Barroso, deputy director of research at Teneo, in a note. The process by which the government can put Article 155 into effect takes about a month to complete.

Puigdemont said Catalonia will declare independence if the government goes forward with triggering Article 155. “As both sides battle for control of the narrative, there will be no quick resolution to the ongoing standoff between the central government and the Catalan authorities,” said Barroso.

To be clear, not everyone in Catalonia wants separation. There have been pro-unity protests since the referendum, in which 90% voted for independence, but turnout was under 50%.

Puigdemont himself is being pulled in several directions — under pressure from hardliners who want to press ahead with separation, and from others who seek dialogue. The Catalan president has repeatedly asked for dialogue with Madrid, to no avail.

As Barroso theorized, Rajoy may be hoping to drag the situation out for some time. In that way, he could exploit for political advantage the damage occurring on an economic level, as well as emerging fractiousness in Barcelona and throughout Catalonia. Several major companies, prominently banks, have announced their intention to look into, at a minimum, moving headquarters out of the region.

Among items that Rajoy could ask the Senate to vote on Saturday, many believe, is a call for early elections to Catalonia’s regional parliament, while others have speculated that he could ask to take control of the local police force there.

People line up outside a La Caixa bank branch to withdraw money as part of a protest against a move of the bank's HQ out of Barcelona. Reuters

What’s the atmosphere in the streets? In Barcelona and the rest of Catalonia, as well as in Madrid, protests have been held on both sides of the crisis. Protests in Barcelona have been seen this week over the detention of two political activists arrested by the central government. Madrid has been criticized for its heavy-handed action — via the federal police force — prior to and during the October referendum.

A separatist group in Catalonia was calling for a “run on the banks" on Friday, in which Catalans would withdraw as much as they could from banks that have threatened to pull headquarters out of the region. (Some participants opted to withdraw the symbolic figure of 155 euros, as in Article 155.)

“As far as we can see, the bank run did not have a great success rate. Not too many people participated in the idea. It would be like shooting themselves in the foot, so I guess most people are still reasonable,” said Predrag Dukic, senior equity sales trader at CM Capital Markets in Madrid, in emailed comments.

Dukic said his firm did not forecast any immediate implementation of Article 155, given the procedural requirements. But he added that he didn’t expect a “positive surprise,” under which the Rajoy government avoids activating that nuclear option.

Analysts expect only further social unrest if and when Article 155 is put into play.

What’s been the reaction?

Spain’s IBEX 35 index IBEX, -2.85% has had its ups and downs as the crisis has evolved, most recently drifting between gains and losses on Friday.The euro EURUSD, -0.67% has also come under pressure as the standoff continued.

“With uncertainty potentially mounting after Spain’s government triggers Article 155 this weekend, the euro remains exposed to downside risks,” said Lukman Otunuga, research analyst at FXTM, in a note to clients on Friday.

“Investors should keep in mind that although the Catalan drama is limited to Spain, it could still spark fears over the rise of other separatist movements in Europe. Such a situation is likely to threaten the stability of the European Union,” Otunuga added.