RISING tension between Madrid and Catalonia reached a new peak yesterday with the announcement by the Catalan president, Artur Mas, that he plans to hold an independence referendum on November 9th next year. Flanked by leaders of parties that hold two-thirds of seats in the region's parliament, Mr Mas launched the biggest challenge to Spain's internal structure in recent history. The Catalans, he said, are “a people who want to decide for themselves on their own future”. But those expecting Catalonia to follow Scotland, which votes in September on separation from the United Kingdom, into a formal and binding decision on independence must think again. Unlike Britain's prime minister, David Cameron, the Spanish prime minister, Mariano Rajoy, does not want a referendum or any other kind of vote that Mr Mas, who terms his proposal a “consultation”, might organise. The government of Mr Rajoy’s conservative Popular Party (PP) government can and will block it. “I guarantee this referendum will not happen,” Mr Rajoy said. He has the backing of Spain's main opposition party, the socialists, and will have the proposed referendum suspended by the constitutional court as soon as it is formally approved by Catalonia's government or parliament.

Mr Mas is expected to bow to the court's decision and, so, cancel the referendum. He can then be expected to declare that the next Catalan regional elections will be, in effect, a plebiscite on independence. But those elections might not be held until 2016. It is impossible to predict the result or what would happen afterwards, especially as the Madrid government may have changed by then. Spain's thorniest issue, in other words, will not be resolved for years.

The new stand-off takes the Catalan problem into uncharted waters. The vast majority of Catalans favour a referendum. But Spain's constitution from 1978 does not offer them a right to self-determination. Nor, insists Mr Rajoy, does it allow any kind of consultation or referendum that is not approved by Madrid.

Polls show that, in the space of just a few years, support for independence has shot up to 56%. But pollsters also see a significant number of waverers. Enric Juliana, an influential columnist of La Vanguardia, a Barcelona newspaper, says many Catalans fluctuate daily, waking up separatist and going to bed federalist. The latter is a solution proposed by Spain's socialists, but frowned on by Mr Rajoy. And even within Mr Mas's nationalist Convergence and Union (CiU) coalition there is a strong sector opposed to outright independence.

With his coalition divided, Mr Mas is increasingly dependent on the separatist Catalan Republican Left (ERC) party for support. ERC currently props up his minority government and would have forced elections if Mr Mas had reneged on his promise to call a referendum on independence next year. Polls also show that ERC is now more popular than CiU and could oust it from its historic position as Catalonia's most popular party. The independence row has fractured the Catalan political panorama, driving voters towards parties more clearly defined as pro or anti independence.

There is nothing like the word “no”, pronounced from Madrid, for inflaming separatist passions. And blocking the referendum does nothing to resolve the growing pressure from Catalans for a change in their relationship with Spain. Mr Rajoy has no plan for fixing the problem. The socialist proposal for constitutional reform to turn Spain into a federal country (a fix that suits some Catalans) would eventually require backing from the PP. Solutions, it seems, will have to wait until after a general election in 2015. In the meantime, the fractures appearing in Catalan society, and between Catalans and other Spaniards, will grow.