I will just make this point and then I will give way.
The Prime Minister has pretended that her customs proposals achieve that. I listened carefully to what the Minister for the Cabinet Office said about amendment (a). He said that, under the political declaration, the benefits are already there, because it notes that the single customs territory in the Northern Ireland backstop obviates the need for rules of origin checks. So the political declaration notes the backstop, which is the contentious bit of the withdrawal agreement. I concede that that is a form of customs union, because under the backstop that single customs territory obviates the need for rules of origin checks. The declaration goes on to say—this goes to the heart of what the Minister for the Cabinet Office just said—that if we build and improve on that customs union for the future partnership, we can continue to avoid customs checks.
Let us unpick that. If we build on the backstop, which is the bit that, as I understand it, many Government Members do not like, we can avoid customs checks. So, the temporary backstop—hopefully never to be used; only an insurance policy—has to become permanent, turbocharged and the foundation stone of the political declaration in order to get the protection of a customs union. That is precisely what the political declaration says.
I am not sure that the Minister for the Cabinet Office has explained that to all the Members behind him. If his proposition is that the backstop is just a short-term, temporary measure, whereas it is actually an essential foundation of the political relationship, I think that might be met with a particular response. The pretence that the political declaration equals the same as a customs union goes against the Government’s stated aim to be outside a customs union.