Madrid’s eight-day deadline for Catalonia to drop its independence bid could prove to be fruitless, according to political analysts, who believe that pro-separatist Catalan President Carles Puigdemont will not back down.

Speaking in the Spanish capital on Wednesday, Prime Minister Mariano Rajoy warned that if the Catalan government refused, he would suspend the region’s autonomy and rule it directly.

Antonio Barroso, deputy director of research at risk consultancy Teneo Intelligence, said that “it is unlikely that Puigdemont will alter his position.”

“(Puigdemont’s) first reaction has been to insist on establishing a ‘bilateral dialogue’ with Spain with ‘no prior conditions’; backpedalling on independence would only lead to an even bigger disappointment within the secessionist camp,” he said in a note Wednesday.

“Given that Rajoy cannot accept a bilateral discussion without Puigdemont backtracking first on independence, the most likely scenario is that the prime minister activates the next steps of Article 155 (the so-called ‘nuclear option’), which will probably happen within the next 48 hours.

An alternative, less likely scenario is that Puigdemont’s ambiguity further angers the more radical elements of the secessionist movement, leading to its implosion and early regional elections in Catalonia.”

Rajoy said Wednesday that Catalonia needed to clarify whether it had declared independence or not, following an ambiguous address by the Catalan leader on Tuesday in which he seemed to declare independence and then suspend it, calling for dialogue with Madrid.

Later on Wednesday, Rajoy told Spain’s parliament that the Catalan government had until Monday, October 16 at 9:00 a.m. London time to answer the demand, according to Reuters. If Puigdemont was to confirm he did declare independence, he would be given an additional three days to rectify it, until Thursday, October 19 at 9:00 a.m. London time.

In a televised address, Rajoy said that that if Catalonia had declared independence, he was ready to invoke the much-vaunted “Article 155” of the Constitution to seize powers back from Catalonia, sacking the regional government and calling fresh elections.

Article 155 has never been invoked before but as tensions have grown between Spain and Catalonia a constitutional crisis has become more of a possibility. If Puigdemont refuses to reply to Spain’s demands, Rajoy is expected to submit a list of actions that the government will take under Article 155 to the Spanish Senate.

“The list must then be debated and approved by a specific committee, after which it will be sent to the plenary for discussion and a final vote,” Barroso explained.

“As Article 155 has never been implemented before, its timeframe is unclear. However, some estimates consider that the whole procedure could be wrapped up in five days,” he added.

The Spanish government’s ultimatum to Catalonia puts more pressure on the regional government which is now stuck between a rock and a hard place.

On one hand, Puigdemont is being pressured by more radical elements within Catalonia’s political establishment — such as the far-left Popular Unity Candidacy party (CUP) — to push ahead with independence. He cannot forget too that 90 percent of around 2.26 million Catalans voted for independence in a symbolic referendum his government held on October 1.

On the other hand, an independent Catalonia would find itself isolated politically and economically, outside the European Union and un-recognized by other European countries. Already several businesses have said they would relocate outside of the region.

Puigdemont faces pressure from Spanish politicians too who say he has to go. Albert Rivera, president of Ciudadanos, an opponent of Catalan independence and ally of Spain’s ruling People’s Party (led by Rajoy), told CNBC Wednesday that new elections were needed in the region, saying “we need a president that will decide to come back to democracy, to come back to the constitution.”