Some are still writing to me saying the referendum was advisory, that it could have been the first of two, that it did not entail leaving the single market and customs union etc. Let’s have another go at explaining it.
The government leaflet said
“A ONCE IN A GENERATION DECISION (in bold, decision not advisory, once only)
This is your decision. The government will implement what you decide”
It could not have been clearer
Much of the text was about trade and economics. It made clear we would be outside the single market, and set out why it thought that would be negative.
It also was based on the premise that we would be outside the customs union, though it did not say that directly. It went on at length about the need to negotiate a trade agreement with the EU after leaving, saying it would take time and be partial. You would not be able to and would not need to negotiate a trade deal with the EU if you were still in the Customs Union!
It was made clear by Remain in the campaign that leaving meant leaving the single market and customs union. Leave understood this and talked about the advantages of the UK being able to strike tariff free trade deals elsewhere which you could not do if still in the Customs Union.
The Conservative Manifesto of 2017 expressly ruled out staying in the single market and customs union. The Labour Manifesto set out a detailed independent UK trade policy which you could not do from within the single market and or customs union with the EU.