One year after Prime Minister May handed her Article 50 letter to President Donald Tusk, Fabian Zuleeg discusses the chances of an exit from Brexit.

No majority for Hard Brexit: Since the results of the Brexit referendum on 23 June 2016 were made public, there have been hopes that an exit from Brexit could eventually prevail. Indeed, the final decision-making body remains the House of Commons and there appears to be no majority for the hard Brexit outcome imposed by the UK government.

Shift in public opinion: More recently, a slow shift in public opinion and the increasing recognition that a hard Brexit jeopardises the open border in Northern Ireland have emboldened once again those that see a chance that Brexit might not happen in the end.

Convincing margin? Any swing to remain would have to be ascertained in a general election and/or a second referendum. Even if there was sustained, broad and effective campaigning to stay in the EU, there is no guarantee that it would be won, let alone with a large and convincing margin.

EU reforms? Even among the supporters of an exit from Brexit, there remains a marked tendency to reject certain obligations and rules of membership. Staying on as member of the EU without addressing any of the issues raised in the referendum campaign seems a step too far. But there is no political will among the EU27 to further accommodate the UK, and not enough time left to negotiate new reforms. And the British people’s reaction to David Cameron’s ‘re-negotiation’ in the run-up to the referendum shows how limited the EU’s influence is likely to be.

Unanimity? It remains unclear whether the UK can simply withdraw the notification unilaterally or whether the UK needs the consent of the EU27 and the EP. Legal opinion is divided here so a court case in front of the ECJ would be needed to settle the question, costing further time. In case the UK requires the consent of the EU27, any agreement is likely to include significant and unpalatable conditions around the UK’s budgetary contributions and its opt-outs.

Backlash? Even if all the legal, political and practical hurdles were to be overcome, there would be no guarantee on the longevity of the UK commitment to EU membership. After all, no real legal/constitutional safeguards exist that can strongly bind future parliaments. So, in future, one cannot rule out another political backlash, which could lead to an even more chaotic Brexit scenario implemented hastily by a staunchly anti-EU government.

Trust? For the EU27, the UK remaining is thus far from unambiguously positive. While it would prevent the immediate economic costs and, arguably, would show the EU27 and the rest of the world that leaving the Union makes no sense, in practical terms, it might make it even more difficult to find consensus in the EU. In addition, the possibility of the UK restarting the process would always be in the back of leaders’ minds.

Time? Despite the uncertainty and despite the negative implications of Brexit, the UK will in all likelihood leave the EU in March 2019. There is only a very slim chance of reversal in the time left.

Crunch point: The real crunch point for the UK government will come when the House of Commons decides on the Withdrawal Agreement. If it is rejected, the House of Commons might decide to withdraw Article 50 for tactical reasons but any attempt to play for time will not be acceptable for the EU27. In the end, the EU27 will only react favourably to a reversal in direction if it is backed up by a sustainable, concrete and unambiguous decision in the UK.

The full policy brief can be found at http://www.epc.eu/documents/uploads/pub_8437_lastchancebrexit.pdf?doc_id=1970