Those who hoped that the UK’s Brexit negotiations might be drawing to a close with the publication of the withdrawal agreement will have been disappointed by the political declaration that accompanied it. It shows the terms of our future relationship with Brussels have so far only been discussed in very broad terms.

Among the many issues still to be resolved is the question of future extradition arrangements. Inside the EU, these are currently governed by the European arrest warrant (EAW), the fast-track procedure rushed into force in 2004 during the war on terror.

By applying the principle of mutual recognition between EU states, the EAW has reduced the expense and time involved in extradition proceedings. Courts are expected to treat the rulings of their EU counterparts as their own, allowing extradition to take place without prima facie evidence, executive approval or a full examination of the facts.

Theresa May on Political Declaration: UK will leave EU agricultural and fisheries policies

There have been clear efficiency gains as a result. The government has estimated that it takes, on average, three months to extradite someone using the EAW compared with 10 months for non-EAW extraditions. The ability of British criminals to evade justice in certain EU jurisdictions has been removed. Yet these gains have come at a cost to human rights.

Mutual recognition assumes that participating states adhere to the same high standards of justice. In fact, cases handled under the EAW have thrown up numerous examples of significant abuses, including instances of police brutality, the fabrication of evidence and conditions of detention that amount to inhuman and degrading treatment.

The fiction of equal justice at the heart of the EAW is revealed in the failure of several participating states to respect their obligations under the European Convention on Human Rights (ECHR). In 2016 alone there were 360 rulings in which the European Court of Human Rights identified at least one violation of the ECHR by an EU member state. These included 86 cases of inhuman and degrading treatment, mostly to do with conditions of detention, and 74 cases in which the right to a fair trial was denied. Two EU countries accounted for more than half of the cases of inhuman and degrading treatment – Romania and Greece. Romania was also the worst offender in denying the right to a fair trial, followed by Bulgaria.

Perhaps even more troubling is growing evidence that some EU states are willing to pursue politically motivated extraditions. The EAW removed the political offences exception that normally applies in extradition agreements on the basis that EU governments don’t use the law to persecute their opponents.

That assumption was shattered by the decision of the Spanish authorities to pursue Carles Puigdemont and other leaders of the 2017 Catalonia independence referendum using the EAW. A German court in fact ruled that Puigdemont could be extradited and only a change of government in Madrid stopped it happening. There are at least two Romanian cases with significant political dimensions currently before the UK courts.

The rise of authoritarian populism in many parts of Europe means that the threat to standards of justice is likely to grow. Concerns about judicial independence led the European Commission to initiate infringement proceedings against Poland in July this year and the European parliament voted to pursue disciplinary action against Hungary under Article 7 of the Treaty on European Union two months later. The governments of both countries have followed the standard authoritarian playbook in packing courts, limiting media freedom and attacking civil society. Others are in danger of following suit.

In considering a post-Brexit extradition deal, the UK should avoid reflexively favouring arrangements that most closely resemble continued EU membership. While a system based on mutual recognition made sense at a time when European countries appeared to be converging around a shared set of democratic norms, the aim now should be to uphold the primacy of human rights and ensure that the UK is able to provide refuge to those fleeing injustice abroad.

The UK has played this role before, most notably during the Victorian era and again during the Second World War and the Cold War. It should be ready to do so again.

Support free-thinking journalism and attend Independent events

Although remaining part of the EAW will not be an option for the UK if it ceases to be an EU member, the political declaration suggests a preference on both sides for an arrangement that replicates many of its features.

Iceland and Norway already have an agreement with the EU that borrows many of the EAW’s features, including the principle of mutual recognition. A better option for the UK would be to dispense with mutual recognition altogether and build a new agreement that sought to maximise efficiency without compromising standards of justice.

That would allow us to restore the requirement on requesting states to provide prima facie evidence of guilt and allow courts to give full consideration to the human rights implications of each case. Although there would be an inevitable reduction in the speed with which extradition requests could be processed, the gain in the UK’s ability to provide a haven of liberty at a time of rising authoritarianism would more than justify it.