Nineteenth-century Britain was an interesting place for a European cosmopolitan. Especially after the upheavals on the continent in the 1840s, statesmen and others who had found themselves on the wrong side in political struggles flocked here. The best known examples were revolutionaries such as Louis Kossuth from Hungary, Alexander Herzen from Russia, Giuseppe Mazzini from Italy, and Louis Blanc fleeing a vindictive France after the fall of the Second Republic. But there were also those ousted by revolutionaries, such as the Empress Eugénie after the debacle at Sedan.

What is interesting is that this was regarded as perfectly normal. Foreign public figures of this kind were technically here on sufferance and could be asked to leave at any time, but provided they behaved themselves and did not try to foment revolution they were generally welcome. Even if they were asked to leave there could be no question of extraditing them back to their home countries.

One regime’s sedition is another’s constitutionalism

This was partly because of a patriotic, if rather ill-informed, belief that English legal and constitutional procedures must be innately superior to continental varieties. This belief continues today, though happily in decline (a few diehard Brexiteers can still be heard telling anyone who will listen that because of the Napoleonic system you are guilty unless proved innocent in France and other European countries). Another reason was that there was genuine reason to doubt if enemies of some European regimes would get fair treatment. Few would have had much confidence in, say, the good faith of the regime of Ferdinand II of the Two Sicilies (known as il re Bomba from his habit of using explosive shells against political opponents) were his political opponents to be delivered into his clutches.

But the matter went further. Government and public opinion accepted that even if it was a good thing for states to co-operate in suppressing crime generally through extradition, this stopped short of state offences. It was no business of nations to do each other’s dirty work in suppressing subversion or sedition, since one regime’s sedition was another’s constitutionalism. The division of the world into nation states, and the limitation of their sovereignty to events within their borders, was an essential bulwark of liberty and political pluralism. This thought process culminated in Britain’s Extradition Act of 1870, which not only made extradition subject to a political veto but barred completely rendition for offences “of a political character”.

This is all relevant because this issue has raised its head again, this time in connection with the Catalan leader Carles Puigdemont and his allies. But, unfortunately, the wholesome view of the nineteenth century has been largely left behind.

Indeed, there is a curious nineteenth-century air about the whole Puigdemont affair. In 2017 Sr Puigdemont tried, by holding a referendum illegal under Spanish law and calling openly for secession, to tear Catalonia away from Spain. He failed and, in an episode reminiscent of an Anthony Hope novel, he had to slip away from the Catalan parliament over a deserted border crossing into France with the Spanish police hot on his trail.

From there he was spirited away to Belgium where he announced that the struggle for freedom would continue. Legal attempts to bring him back to Spain on a charge of rebellion foundered on technicalities. In 2019 he stymied further proceedings by being elected to the European Parliament and thereby obtaining immunity from prosecution. Another separatist, Clara Ponsatí, against whom proceedings were pending and whom Spain also wished returned, was also elected.

It is not our job to aid other states in washing their dirty political linen

The matter flared up again last week when the European Parliament (since Brexit not keen on ideas of secession) voted to strip Sr Puigdemont and Sra Ponsatí of their immunity. Spain immediately sought to enforce a European Arrest Warrant (known as an EAW) which it had taken out against Sra Ponsatí, and is likely to issue one against Sr Puigdemont. And herein lies the difficulty: when the EAW procedure was introduced, it required extradition within the EU for any crime carrying more than one year imprisonment. It did not matter whether the crime was political or not and the process was simple and bureaucratic (the only check available to state authorities being a judicial check whether the process was formally in order). If it was, then only proof deemed positive of likely political prejudice at trial was allowed to prevent it.

The result, contrary to any old-fashioned ideas about the protection of political dissidents, Mr Puigdemont now faces is the prospect of being bundled willy-nilly on a plane bound from Brussels to Madrid to face trial. There would be nothing either he or the Belgian government, however well-disposed it might be, could do about it.

This is bad enough and shows the increasingly authoritarian nature of the EU. But there is worse. You can’t even take comfort in the idea that since Brexit this doesn’t affect us. It does. Remember that the UK was a member of the EAW system as much as any other EU member state until December 2020.

Clara Ponsatí is based in the UK as a respected economics academic at St Andrews University and, since the EAW against her was issued when we were still in the EU, she now faces the prospect of arrest on Scottish soil on account of her political activities in Spain, followed again by forcible repatriation there to face trial.

Indeed, matters may go even further than that. Brexit technically took the UK out of the EAW system, but the Trade and Co-operation Agreement immediately replaced it with something similar, including a complete bar on refusing extradition to EU states on the grounds that the alleged offence was political. So, if an EAW were to be issued tomorrow against Sr Puigdemont and were he to seek refuge here, it seems we would have no choice but to have him arrested and returned to Spain for trial.

We need to make it clear that our attitude remains as it was in the 1850s

This abandonment, not only of the prohibition on extraditing political dissidents but of the right of our elected government to intervene on political grounds to stop it, is deeply disturbing. Even if he would be impeccably tried if returned, political diversity and free speech raise very strong arguments in favour of allowing a dissident to escape to another state without fear of immediate arrest. Even within Europe, whatever EU enthusiasts say about the forging of common European values, political climates vary: think Ireland and Latvia, Sweden and Hungary. The idea that Sweden should have to return a Hungarian refusenik, on the basis that we all follow common values and should therefore trust to the decency of each other’s governments, is deeply unattractive. And the same thing goes for this country as regards a Catalan separatist.

There is one possible ray of light. The provision about political offences in the Trade and Co-operation Agreement is not irrevocable. The UK can, if it wishes, give notice to the EU that it will in future refuse to extradite in respect of non-terrorist political offences. It should have the courage of its convictions and do this immediately. We need to make it clear that our attitude remains as it was in the 1850s: it is not our job to aid other states in washing their dirty political linen or to help prosecute offences like sedition or rebellion.

It would be a matter of considerable pride if next time an affair like the Catalan debacle arises, we can simply say of a future Puigdemont or Ponsati who chooses to come here: “This person is following in the footsteps of Mazzini and Kossuth, and we are proud to say we will follow our tradition of allowing them to express their views here. They will not be returned.”