Spain's parliament votes on Tuesday on whether to allow a request from Catalonia to hold a referendum on independence – a request they are set to reject overwhelmingingly.

The parliamentary confrontation threatens to widen the gulf between the central government in Madrid and Catalan leaders looking to break away from Spain.

On Tuesday, Spanish MPs debate and vote on a proposal from Catalonia's regional parliament to hold a referendum that the Catalan government, lead by Artur Mas, has already set for 9 November.

The Spanish prime minister, Mariano Rajoy, has repeatedly called the referendum unconstitutional, arguing that polls on sovereignty must be held nationally. His position is backed by Spain's constitutional court, which ruled last month that a referendum in the powerful north-eastern region could only take place if changes were made to Spain's constitution.

Tuesday's petition is expected to be voted down by 300 of the 350 parliamentarians, including those from Rajoy's People's party and the main opposition Socialists. Anticipating a no vote, Mas said earlier this week he would not attend the debate.

The vote is only the latest chapter in a political stalemate between Madrid and the Catalan government in Barcelona."From here, everything will continue the same. In the short-term, I don't see any significant changes," political analyst Josep Ramoneda told the Guaridan.

Less than two months ago, in a motion brought by the centrist Union for Progress and Democracy party, Spain's parliament torpedoed the Catalan government's independence drive, voting 272 to 43 to reject Catalonia's "right to decide".

The underlying problem, said Ramoneda, is that Spain cannot offer Mas the two elements he's looking for: a redistribution of power and the possibility that one day Catalonians could decide the region's fate in a referendum.

"Without those two elements we continue in a situation of both saying their piece without heading in any clear direction. I don't see a way out," Ramoneda said.

Regardless of the vote's coutcome, Mas has vowed to push forward with the planned referendum in November. "If they say no, they will say no to a law," Mas said on Sunday. "But they can't block the will of the Catalan people."

The latest polls show that roughly half of Catalans support independence.

If Spanish courts shut down all possibilities of a referendum, Mas is widely expected to use the next elections in Catalonia as a de facto referendum on independence.

Spain's deputy prime minister, Soraya Sáenz de Santamaría, said on Friday Madrid was open to dialogue, but reinforced the government's position that the final say on independence cannot be limited to Catalans alone. "Spaniards have the right to decide what Spain is. And only the entirety of Spaniards can decide that."

Fernando Vallespín, a political scientist with Madrid's Autónoma University, believes the opposition Socialists may have found a way to break the stalemate with their suggestion to give Catalonia greater autonomy but not full independence. Doing so would appeal to a large demographic in the region, Vallespín said, particularly those who "don't want to leave Spain but want more out of the relationship between Spain and Catalonia".