What is the goal of the Labour Party’s switch to being in favour of the UK having some form of a customs union with the EU post-Brexit? If it is to avoid border checks, then it is important to point out that customs checks can only be avoided, and free circulation guaranteed, by adherence to Single Market rules. Border checks are carried out not only to satisfy the formalities of import duties, but also to satisfy the technical product regulations which are part of the Single Market. A customs union would guarantee zero tariffs, but zero tariffs can also be maintained in a trade agreement between the UK and EU. A trade agreement would also contain a chapter on customs, to allow comprehensive co-operation and facilitation (which the WTO allows two neighbouring regions to agree). The UK and other member states are already in the process of moving towards more technologically-enabled customs mechanisms including single window, self-assessment and a much greater use of trusted trader programmes. The UK is one of and neighbour to the smoothest and most efficient customs agencies in the world, according to the World Bank. The intrusive nature of customs checks will gradually decline in the future, as technology makes border arrangements more and more efficient. So if the goal is free circulation as it now exists, it would appear that the Labour Party proposal can only work as a customs union plus adherence to Single Market rules. Turkey has agreed to harmonisation with all relevant Single Market rules for this reason. Indeed, in the case of Turkey, in areas where they do not adopt these rules (for example, agriculture) there are checks and delays at the border between Bulgaria and Turkey. In his speech, Jeremy Corbyn also expressed a commitment to not be bound by European rules on state aids, competition, and procurement. The problem is that these are precisely the rules that the EU considers critical to the functioning of the Single Market, and it is impossible to conceive of a situation where the EU would voluntarily agree to allow a party to be part of the Single Market or a customs union and not apply them. Why would they agree to tariff-free and frictionless trade with a country that subsidises it manufacturers? Furthermore, even in a free trade agreement between the UK and EU, it is in both parties’ interests for these rules to apply to both parties as they deliver competition on the merits which is critical for economic growth. Developing an independent trade policy is a difficult matter. The UK will require flexibility to do this. Behind the border barriers particularly damage services trade, and for the UK to be able to reduce these barriers it will have to be able to use all of the leverage it has. This does not mean that the UK has to change anything – it may choose not to do so if the gains from a reduction of barriers are not worth making the changes that would have to be agreed to secure it. That is a matter for the British government accountable to the British people. The kind of customs union and, inevitably, Single Market proposal that Jeremy Corbyn put forward would make any trade negotiations with others, any unilateral changes to improve our regulatory environment, and any activity in global organisations such as the WTO all but impossible. The only logical step to take if you are going to be in a customs union and subject to the rules of the Single Market is to remain in the EU. It is natural for political figures caught in the maelstrom of Brexit to search for some sort of compromise. But the customs union and partial customs union proposals which have been recently floated have been false compromises because if adopted they eliminate the benefits of Brexit and turn it into a damage limitation exercise. There will be a time for compromises. If we are able to agree sensible regulatory recognition and divergence management mechanisms with the EU, we will need to assess what our needs are and whether potential increases in EU barriers are outweighed by gains elsewhere. That is the condition of any sovereign nation with an independent trade policy. We will, in short have to decide who we are as a country – again a matter for the British people. For a logical approach to Brexit there really is only one choice. Either the UK has control over tariff schedules and regulatory autonomy so that it can – and other countries believe it can – execute an independent trade policy. Or it should remain in the EU. Anything else will be worse than membership. The problem with remaining in the EU is that, aside from the implications of disregarding a referendum vote, politically it is hard to conceive of a situation where the UK could do this and expect the same or better terms than it has now. Any proposals offered, if they are to be seriously considered, must make Brexit more than just a damage limitation exercise. If that is all they do, then they should be rejected.