A customs union would be a betrayal of Brexit

If those two conditions are met, Brexit will have happened. If not, we will end up stuck in a halfway house, with limited upsides and too many downsides. Talk of red lines is misleading; compromise is possible. There’s no reason why we shouldn’t bind ourselves by treaty to close collaboration on things such as nuclear energy regulation, or in some cases voluntarily shadow EU standards that make it easier to export goods or services to the continent. But the reality is that almost all economic growth for the remainder of this century will happen outside the EU, and we must be able to prioritise the future without being debilitated by the past and present.

It is also clearly the case that Britain needs to shake up many of its own regulations and taxes to become more competitive. Countries around the world have successfully engaged in unilateral liberalisation; most recently, the United States has cut its taxes and begun a process of regulatory reform that has radically improved business confidence. It would be utterly unacceptable were Britain to have to beg for permission from Brussels to do something like this after we quit the EU.

This is why it is a non-negotiable condition that the UK leaves the customs union. No Eurosceptic has ever wanted to remain part of it. Brexit always meant regaining the freedom to trade: even Norway is allowed to do this. The Tory rebels in Parliament must back down. They mustn’t do Jeremy Corbyn’s work for him. They have to understand that the future of the Conservative Party rests on making Brexit work – and that Brexit will only work if Britain is fully outside the EU, outside the customs union and free to seek its fortune in the global marketplace.