The new Prime Minister will have their work cut out in Brussels

Those aiming to be Prime Minister need to be careful about what they say in the upcoming campaign, in case they make promises they can’t keep: despite what Boris Johnson may say he intends to do, the EU has said very clearly that it isn’t in the market for renegotiating the current Withdrawal Agreement. That means the incoming Prime Minister will face the same immediate issue as the current one: a choice on whether to try again for parliamentary approval of some version of the current agreement or to pursue a no deal exit.

But whether the UK leaves the EU with a deal or not, the next step will inevitably be heading to Brussels to start talking again. The first task will be to rebuild the goodwill amongst EU partners that has been worn down by the months of indecision and parliamentary drama – and which could take a further beating in the leadership campaign. And then the new PM will need to decide what they want the next deal with the EU to look like.

Leaving with no deal doesn’t mean the end of talks

If the new Prime Minister decides to take the UK out of the EU without a deal, relations would be damaged and it may be a while until the two sides are prepared to talk in detail. But they would need to – the temporary contingency measures the EU are putting in place are nowhere near a full relationship and may only last a couple of months after 31 October.

But the EU has said that its first request in any talks after a no deal exit will be around citizens’ rights, the UK’s financial settlement and the Irish border – aka the Withdrawal Agreement. So before getting a deal on long-term arrangements, the UK will have to find a way forward on the same issues – in particular, the Irish border backstop – which have led to the current deal being repeatedly rejected.

Getting the same deal from outside the EU will be even more complicated

However, even that won’t be straightforward. Because the UK will no longer be a member state at that point, it will not be negotiating under Article 50 of the EU Treaty, but under Article 218, the rule that governs EU negotiations with non-members. Article 218 sets out a lengthy process for negotiations, requiring a new mandate for the Commission and, in all likelihood, full ratification by the national and sub-national parliaments of the 27 ongoing member states. It will take years before the UK can even sign up to a deal that looks very much like the one on the table.

If the UK leaves with a deal, it can create momentum – but it needs to be ready

If, on the other hand, the new Prime Minister manages to convince enough of their parliamentary colleagues that some version of the Withdrawal Agreement is acceptable – or miraculously agrees a different deal that works for Brussels and London – he or she could rapidly rebuild good will in the EU. That would be a much better starting point for the negotiations on the future relationship. 

But this route presents pitfalls for the UK as well. The EU is currently focused on the outcome of the European Parliament elections, and the allocation of the top jobs at the European Commission. But it has been preparing for talks on the future relationship with the UK for months now – after all, it was expecting them to begin on 1 April. So the EU will be ready for talks as soon as the UK has left.

The UK, on the other hand, has yet to show that it is anywhere near ready. As we have argued, unless the UK takes a clear, informed decision on what it wants from the future relationship, it will fail before it has even begun. As well as a clear understanding of its objectives for the future relationship, the Government needs to be clear on who is responsible for what in the next phase of talks. The new Prime Minister needs to have a clear sense of what they want before talks begin and not, like Theresa May, decide halfway through the process.

Changing the Prime Minister doesn’t change the problems they face

Theresa May’s successor will face the same issues that she has, but with less time to deal with them. The would-be-prime-ministers will now be thinking about how to woo their parliamentary colleagues and the party memberships. When they have got the keys to Number 10 their immediate focus will be on setting up their Government and dealing with Parliament. But leadership contenders need to remember that the fundamental issues of Brexit haven’t changed – and that their approach to Brussels, and relationships with the leading EU players, will define their premiership in the same way it has defined May’s.