On the face of it, Spain and the United Kingdom have much in common. Both are maritime, quasi-federal states and former empire-builders, who in the postwar era have faced the prospect of disintegration, as peoples in their peripheral nations have sought varying degrees of separation. In each case, the largest central nation, Castile and England, has resisted violent campaigns of national liberation, in the Basque country and Northern Ireland respectively. That’s why the IRA and ETA made common cause: it’s normal for separatist groups to forge such allegiances. It’s also the reason why the two nationalist movements in countries now seeking peaceful means of withdrawal, Catalonia and Scotland, have paid much attention to each other’s fortunes. No wonder that Catalan leaders have been looking seriously at holding their referendum at about the same time as Scotland’s, which takes place on 18 September 2014.

Is such a comparison valid, though? Is an alliance between Catalonia and Scotland useful? In each case, I would say no and no. The reality that Scotland is looking increasingly likely to vote ‘no’ is bad news for the Catalan independence movement. If ‘Catalonia is not Spain’, as the familiar banner reads, it isn’t Scotland, either. It’s not entirely coincidental that the Catalan parliament announced a referendum in January, 12 months after London agreed to one in Scotland. Catalans have been greatly enthused by the progress made by the Scottish National Party (SNP) under the charismatic Alex Salmond. Yet it has increasingly become an unreciprocated love affair. Salmond has so far kept his distance. There’s no point in making enemies with Madrid at this stage, as, unlike London, a belligerent Madrid has not agreed to an official referendum and the outcome in Catalonia isn’t binding.

The realisation that Scotland will probably vote ‘no’ (support for independence is at around 30 per cent and falling) is causing many in Catalonia, where secessionists make up a 70 per cent majority, to have a rethink. In January, the influential, left-leaning internet news site VilaWeb made known its concerns: ‘In Scotland, the process is practically exclusively led by the Scottish National Party, which is opposed by an ideologically diverse coalition’, wrote the site’s editor Vicent Partal. ‘In Catalonia, by contrast – and this became clear in the last election – the people don’t want a single party or a single leader to run the process.’ Support for the SNP is actually higher than for independence, which makes sense if you consider the party’s right-wing origins. Many people vote for the SNP north of the border for the same reason they do for the United Kingdom Independence Party (UKIP) south of it: they feel alienated from the three main parties who are ‘out of touch’, or they are angered at power exercised far away in London or Brussels. Alex Salmond and Nigel Farage may not be best mates, but they have a similar appeal for similar reasons.

If the Catalan desire for independence is more profound, this is why it’s not leftist-statist like the SNP’s. It’s divided not only between those who want increased devolution, full independence or a version of federalism, but between left and right. The independence movement has two flags: the Esteleda, with the blue triangle being a generic nationalist one, and another that has a socialist yellow triangle. While the Catalan president Artur Mas holds together an uneasy pro-independence coalition between the centre-right Convergence Union (CiU) and Republic Left of Catalonia (ERC), both the conservative government in Madrid and its socialist opponents are against independence. In the words of Glasgow Herald columnist Andrew McKie, who has spent time in Spain, ‘Catalonia is in almost exactly the opposite position to Scotland’. London is giving Scotland the option to leave because it is confident that it won’t. Madrid’s unwillingness to allow Catalonia the option to leave is based on the well-grounded fear that it will. Yet Madrid’s staunch line is also symptomatic of why there is this desire for independence in the first place. If some Scots think they got a raw deal from London in the 1980s, appalling memories of the Franco years still haunt Catalans in these woeful times for Iberia. Between 1939 and 1975, Catalan culture was harshly repressed, the language was banned, as were popular left-wing political parties, while 4,000 Catalans were executed and a further 30,000 imprisoned. This puts the Poll Tax in some perspective.

During the same period, Scots and English fought side by side in a world war, after which Scotland sought and has attained greater autonomy. As the Catalan journalist and business consultant Marc Arza tells me: ‘Catalonia has never played a central role in Spanish affairs. Catalans, in fact, have seldom played a major role in Spanish politics and have been more oriented towards home rule. In Great Britain, Scots played a central role on the Empire expansion and consolidation while in Spain Catalans were marginalised, expressly forbidden from doing business with the American empire.’ The leading nationalist politician Xavier Solano adds: ‘The United Kingdom is one of the world’s oldest and most mature democracies. It has respected the national identities of each of its four constituent parts. Spain, on the other hand, has economically punished Catalonia and kept it hidden from the world since 1714.’ A particularly sore point for people in Catalonia is that their territory accounts for over 20 per cent of Spain’s GDP but only eight per cent is ploughed back into it by the state – and that the Catalan community represents 16 per cent of Spain’s population.

The reason why independence would be dangerous for Scotland is demonstrated by the fact that it has no equivalent of FC Barcelona – a national football club. The fans of the two big Scottish clubs wave British and Irish flags respectively. Without England to blame for every woe, Scottish nationalists will fissure on the old fault lines of Catholic and Protestant, Glasgow versus Edinburgh, Highlanders and Lowlanders. Independence for Scotland would also have a disastrous knock-on effect in Northern Ireland, the only place where people use ‘British’ to describe themselves ethnically. The UK I want is not one of petty nationalism and bickering. Here in Britain, the unionist case is stronger than it’s been since the 1960s, especially considering the endless turmoil in the EU and Eurozone. The Britain I want is the one we saw recently when millions of Englishmen raucously cheered a Scot to a British win at Wimbledon.

As for Catalonian nationalists, the sooner they distance themselves from the Scottish issue, the better. They know that it would be wise to bring forward the date of the referendum, if possible. But some caution is advisable. Divorces in which one partner is unwilling to part get nasty: witness Yugoslavia. And why replace one set of rulers in Madrid with those in Berlin and Brussels? The only thing Scotland and Catalonia really share is that an extended version of devolution – ‘devo-max’ – would be the best option for both. How Barcelona will get this from Madrid is another matter altogether.