Brexit — velvet divorce or messy breakup?

We use a ‘scenario tree’ approach to look at the possible outcomes of the negotiations around the UK's exit from the EU. Given how little common ground there is between the two sides, we find that a relatively loose relationship is the most likely outcome, with the UK set to leave the EU in early‐ 2019. The negotiating positions of the UK and EU are diametrically opposed. The UK wants to end the free movement of labour, cease making contributions to the EU budget and regain ‘sovereignty’ from Brussels, while retaining as much access to the single market as possible. But the EU's starting position is that single market access is dependent upon agreeing to the four freedoms and that this is non‐negotiable. So far all signs are that the UK will prioritise the ability to control immigration over single market access. Thus remaining a member of the EEA is very unlikely to be viable over the longer‐term – our scenario tree analysis gives it a probability of just 6% – although it may be adopted as an interim step. Remaining part of the customs union is also unlikely (18%) as it will preclude the UK from making FTA with third countries. If the EU takes a mercantilist approach, it will have little incentive to come to an agreement with the UK over single market access for services, given the UK's large trade surplus with the EU for these activities, implying that UK firms may face growing non‐tariff barriers after the UK has left the EU. The UK's large deficit on goods trade with the EU gives a better chance of agreeing a FTA for goods, though with any FTA requiring agreement from all 27 EU members, the UK would have to be prepared for lengthy negotiations and make extensive concessions. Therefore, we think that a reversion to WTO rules (37%) is slightly more likely than agreeing a FTA (36%).