In Catalonia, as in Scotland, a referendum on independence is the best course for unionists

In the north east tip of Spain people watched with envy as David Cameron signed his historic deal with Alex Salmond guaranteeing a referendum on independence. For in Catalonia – a region simmering with newly fledged independentistes – the path to a similar vote on autonomy is marred by an uncompromising relationship with central Spain.

In Britain Cameron has faced strong criticism from the right for even offering Salmond the chance to fashion a break from the United Kingdom. Those closer to the centre have questioned the 2014 date, which buys Salmond plenty of time to win over the largely unconvinced Scots. But two years of democratic dialogue could also muffle the cries from nationalists who rely on conflict to feed the flames of the independence movement.

Catalonia, although historically different, offers a helpful parallel. A stubborn lack of negotiation over autonomy has allowed nationalist sentiment among Catalans to swell as demands for their own referendum grow. September saw record numbers take to the streets in Barcelona calling for independence and carrying a long list of grievances with central Spain. Deep cuts, subsidies to Madrid and unequal distribution of tax revenues all came to the fore in a march which put the question of independence on the national agenda.

Similar calls for a compromise over the relationship between Catalonia and Spain have typically been dismissed by Madrid in the past. But recently, demands have been growing slowly louder as the financial crisis hit home in the region. This culminated in the unprecedented protest which was backed by warnings from the president of the Catalan Parliament, Artur Mas, that if demands were ignored, Spain would face a break-up.

Madrid’s reaction was customarily firm, with conservative president Mariano Rajoy dismissing the 1.5 million-strong protest as nothing more than an unwelcome distraction in a time of real economic emergency. The president’s inflammatory remarks were followed by Spanish Army Colonel Francisco Alaman offering his comments: "Independence for Catalonia? Over my dead body… and those of many soldiers."

Provocative words to say the least. ‘Threatening’ is the word used by commentators in Catalonia where the appetite for independence has continued to grow.

The reaction from Madrid was followed by the decision by Mas to call snap elections with the promise of a referendum on independence during the next four-year term. More recently, the Catalan president and leader of the ruling Convergence and Union party added plans to draw the European Union into the row by suggesting that the referendum question should be phrased: "Do you want Catalonia to become a new state within the European Union?"

The move pulls up all sorts of legal questions in Spain and the EU. Firstly, a referendum would be technically illegal as a direct vote on independence is currently prohibited by the Spanish constitution. Secondly, the EU has no precedent for the break-up of a member state. Furthermore, any new membership application needs the veto of only one other EU state to block entry.

The promise of a referendum has also caught the attention of other autonomous regions in Spain. Regional elections in the Basque country last weekend left separatist coalition EH Bildu as the region's second biggest political group with a quarter of the vote. And with the Basque Nationalist party winning overall, it looks like there may be calls for a similar referendum on independence.

All this while the row over Catalonia is continuing to spiral out of control. Accusations of treason have been levelled at Catalan politicians over their push for an illegal referendum coupled with threats to suspend the region’s current level of autonomy. A Spanish ruling party MEP, Alejo Vidal-Quadras, has even suggested that the Catalan Mossos d'Esquadra police force be taken over by the central Spanish ‘Guardia Civil, while deputy prime minister, Soraya Sáenz de Santamaría, has committed to using the legal powers available to block any Catalan referendum.

The threats from both sides are fuelling tension and stoking nationalist loyalties inside Catalonia where polls show support for independence has climbed to 50 per cent. The uncompromising position from Madrid and reaction from Mas has left the independence movement feeding off a diplomatic crisis. The lack of sensible dialogue about the tabled referendum now threatens to push Spain into constitutional crisis – recruiting many more independentistes in the process.

If the threats continue amid the current climate, support for independence will have grown further by 2014 which may well tip the balance in favour of a split from Spain. And whether a ‘yes’ vote is deemed constitutional or not, the implications would be hugely unsettling for the region, Spain and the EU.

Unionists in Britain can be thankful that they have two years of considered debate ahead. Attempts to ignite the more reactionary and incendiary forms of nationalist sentiment have arguably been doused by opening the door to discussion. The true benefits and costs of a divided United Kingdom may be reasoned with free dialogue leading to an informed democratic choice. It is an exemplary approach to self-determination and one which may work in Cameron’s favour.