View of Westminster, the Houses of Parliament, and the Elizabeth Tower, commonly known as Big Ben, when the Sun sets in London on September 29, 2017.  (Photo by Alberto Pezzali/NurPhoto via Getty Images)

Parliament has returned this week. Many are looking to MPs to shape Brexit. But how much of the process is within the control of British politicians? Article 50 has been triggered. What happens next is largely out of the country’s hands.

Unless something exceptional and unforeseen happens, the UK will leave the EU by automatic operation of law on 29 March 2019. On the assumptions that this does happen and that there is a withdrawal agreement in place much like the current draft, here are 10 factors that are likely to shape Brexit.

Can the withdrawal agreement take the strain?

This is perhaps the biggest and most immediate unknown factor. The UK and EU are hoping that a bilateral withdrawal agreement will be enough to duplicate the entire practical effect of two complex EU treaties. From 29 March 2019, the UK will no longer be subject to the treaties but it is somehow to continue being bound by EU law and policy for a further 21 months.

The withdrawal agreement may be robust enough to achieve this feat, but any serious legal problems will affect whether the transition period works or not, regardless of any final trade or association agreement. Nothing like this has been tried before. If it does not work, another approach will be urgently needed.

The length of the transition period

This is expected to last 21 months, ending on December 31 2020. From a political perspective, some may want to keep extending the period. But that is not just a question of politics.

Any extension will also be a question of law. Article 50 does not expressly provide for a transition agreement, still less an open-ended one. If a legalistic view prevails, there will be a new cliff edge on that date and nothing short of a full association agreement covering trade and everything else will prevent it.

The Irish border issue

The issue of the Irish border has not gone away, despite seemingly being deferred to the transition period — though the Irish government is rightly insisting on firmer wording for the withdrawal agreement.

If there is no solution at the end of the transition period as to how Northern Ireland can stay within the EU’s customs union and single market when the rest of the UK is outside, then the withdrawal agreement will provide a backstop that Northern Ireland stays in both, whatever the rest of the UK does. Any other solution will have a significant impact on the shape of Brexit.

Free trade agreements

Any free trade agreements the UK manages to negotiate with third parties will determine whether it can stay within the customs union after the transition period.

On the face of it, such agreements are unlikely, as they typically take around five or so years to negotiate. And if they include lower food and other regulatory standards, there may even be political opposition in the UK.

There is also the question of whether Britain will have an adequate customs infrastructure in place by December 2020.

Regulatory divergence and alignment

If the UK moves towards regulatory divergence from EU standards, that will affect its prospects of remaining in the single market at the end of the transition period.

The more divergence, the less the chance. Also relevant will be the extent to which Britain detaches itself from EU regulatory bodies: there is little sign so far that it is in a position to replicate the regulators.

What will be on offer for a follow-on agreement?

Whatever the UK wants or needs at the end of the transition agreement, there is no necessary reason why the EU should comply. Britain’s negotiating position will be weaker than it is now and it may have to take it or leave it.

The EU’s attitude will also be affected by the customs union and regulatory alignment points set out above. If the UK is moving towards free trade agreements and regulatory realignment, it would seem that only a Canada-style deal will be available, if at all.

The scope of the referendum mandate

On domestic matters, the key question is whether the referendum mandate still has force after 29 March 2019. On a strict view (as I set out here), the mandate will be discharged so politics can return to assessing options on merit.

But if a wide view, politicians may still tell themselves that only certain outcomes are the “will of the people”. That will limit the UK’s options.

The parliamentary arithmetic

The Conservative government has a minority in the House of Commons. It is currently kept in power by the Democratic Unionist party of Northern Ireland. This means any vote of no confidence by MPs is unlikely to succeed.

But if the parliamentary numbers change, either because the DUP withdraws support or Conservative pro-EU MPs become more assertive, the government’s position becomes more precarious.

The attitude of the opposition

The government has benefited from an opposition Labour party that generally supports its Brexit policy. The leader of the opposition is no fan of the EU, especially on state aid and liberalisation measures.

So the government has had a free pass on most of the withdrawal measures. But this may change, and a less obliging opposition would want to exploit every Brexit setback.

UK government policy

Tenth on the list, and of least practical importance, is what the UK government says it wants. It can announce that it wants all sorts of bold and ambitious and deep and special partnerships. But this will merely be magical thinking unless it accords with the more significant shapers of Brexit set out here.

And as there is little sign that the UK will be any more prepared for Brexit at the end of the transition period than it has been to date, what happens after 31 December 2020 will be, like now, in the hands of others. That is the reality of “taking back control”.

Get alerts on Brexit when a new story is published

Copyright The Financial Times Limited 2022. All rights reserved.
Reuse this content (opens in new window) CommentsJump to comments section

Follow the topics in this article