Can someone help me out understanding this. Labour/Corbyn requesting a customs union, May's response seems to make sense:
Mrs May does not agree with his first demand on the customs union, and wrote: "I am not clear why you believe it would be preferable to seek a say in future EU trade deals rather than the ability to strike our own deals?"
The existing Political Declaration, setting out the goals for the future relationship between the UK and the EU, "explicitly provides for the benefits of a customs union - no tariffs, fees, charges or quantitative restrictions across all sectors and no checks on rules of origin", Mrs May told Mr Corbyn.
So why are labour requesting this? What advantages does it provide?