Extradition has been a fraught issue in Europe for decades, long before the Catalonia crisis.

London was the safe haven for European radicals in flight from tyrannous governments. As Andrew Katzen of Hickman & Rose points out, the original Extradition Act of 1870 provided that no extradition could occur in relation to offences of a political nature. “The UK became something of a haven for political refugees, with Marx, Lenin and many others seeking asylum in Britain.”

Last week, however, it was to Brussels that Carles Puigdemont and some of his fellow Catalonian nationalists fled hoping, maybe naively, that its “European values” would save them from extradition back to Spain under a European arrest warrant. Whether or not that will prove to be the case remains to be seen. The irony is that were it the Belgian authorities who were attempting such an extradition from London they might conceivably fail on the grounds that imprisonment in Belgium would infringe their human rights.

“Earlier this year the High Court stayed all contested Belgian extraditions pending the determination of an appeal in which ill-treatment was alleged,” Katzen says. “The treatment complained of included poor living conditions and recurrent strike action by prison staff. Belgian prison conditions have been recently described as ‘medieval’. ”

So for the time being, Mr Puigdemont may reflect that he has had a lucky escape by not being incarcerated while waiting a judgment from the Belgian courts on the arrest warrant. But what the case illustrates is the complexity of the extradition scene across the EU — let alone the wider world — given the variety of justice systems. And as Rebecca Niblock of Kingsley Napley explains, it is not just human rights issues that can forestall an extradition. “There are other possible bars to extradition, including the passage of time, the age and health of the accused and the risk of double jeopardy,” she says.

So although, as Katzen observes, “European arrest warrants are notoriously difficult to defeat and there are few European Court of Human Rights pilot judgments against European countries”, it does not mean such an event cannot happen.

That is why the Puigdemont case could be significant. Niblock points out that the accusations of rebellion and secession in the Catalonian independence case must amount to offences under Belgian law. They do not appear in the EU agreed list of offences for which it is not necessary to show criminality in both countries. If the Spanish authorities are determined enough, the Puigdemont case could end up in the European Court of Justice.

There is a catch, however. For good measure, the Spanish authorities have added to the “political” accusations a number of charges of financial crime to give criminal grist to the judicial grind. As Ben Keith, a barrister of 5 St Andrew’s Hill, points out, “Many asylum seekers are excluded from protection . . . because they are accused of a ‘serious non-political crime’. This is an important factor in extradition and political cases because prosecutions can be launched in order to besmirch the name of a political or business rival. In my experience of dealing with political cases from former CIS [Russian Commonwealth] states, the issue of Interpol ‘Red’ notices is a common feature used to try and manipulate the asylum process from afar.”

With Russia the UK authorities and judiciary are aware of this and in most cases are duly suspicious. Keith gives a good example. “Two weeks ago the senior district judge discharged my client who was formerly the owner of a major cheese factory in Russia. She found that the case was politically motivated in that the local politician had managed to force him to sell his business at a huge under-value and threatened him with violence.”

That said, the problem for the UK, as Niblock points out, is that it does not want to be seen as a convenient bolt hole for Russian criminals who believe that the arm of the Russian police cannot stretch here. It might well be that we will see Russians being returned to Moscow in the near future.

But Russia is not the only country regularly trying to haul back its citizens from the UK. Andrew Smith, white- collar crime partner with Corker Binning, explains that even though the UK has an extradition treaty with the UAE, in practice it would be very unlikely for the British courts to return anyone to that jurisdiction under the present regime. Meanwhile with some countries, such as Iran and China, there is no extradition treaty and so extradition “just would not happen”.

Of course, the elephant in the room and the most significant country to which people are regularly extradited from the UK is the USA. One rare landmark exception was Gary McKinnon, the computer hacker with Asperger’s. As Smith points out, it was Theresa May as home secretary who decided not to comply with the US request. But in making the announcement, Mrs May said it was the last time a home secretary would ever be involved in such a way — from then it would be entirely up to the courts. A teasing precedent.

This article was originally published in the Times' website on Thursday 9 November 2017 and the full article can be accessed here.