I am a firm supporter of the Prime Minister’s position on this question, and I will set out why.
I am clear that continued membership of the customs union would represent a breach of faith with the referendum result and with the wishes of millions of Labour voters up and down our country. It would also be a serious misjudgement, given the way it would leave our country bound by EU rules on trade but with no say on them, which would represent the worst of all possible worlds.
The only large country that has a customs union with the EU but that is not an EU member state is Turkey, but Turkey’s customs union is almost unbelievably asymmetric. The EU does not need Turkey’s consent to enter free trade agreements with any other country, and Turkey is obliged to reduce its tariffs with such countries. However, the third country with which the EU enters an FTA is under no reciprocal obligation to open its markets to Turkish exporters. In other words, Turkey has to open her markets but might reap none of the benefits. This is not an academic issue. Turkey finds herself in that situation in her trade with countries like Mexico and South Africa.
In a frank interview last summer with the BBC, the shadow Secretary of State for International Trade, the hon. Member for Brent North (Barry Gardiner), warned it would be a “disaster” for Britain to find itself in that situation. I agree with him, and I wish the Labour party were not now attempting to U-turn on that logic.
In a customs union, Britain would be reduced to taking whatever deal we are handed by Brussels, with no say on the outcome.