In accepting our report’s recommendations 1 and 4, the Welsh Government reiterates its position:

'that we must maintain full and unfettered access to the Single Market and we remain to be convinced that being outside a Customs Union with the EU is in our interests, at least for the foreseeable future.'

However, as we heard from policy think tank Open Europe in Brussels, it would be strange if the UK was in the customs union. Like Turkey, the EU would negotiate trade agreements with third parties without the UK at the table. They also said that if the UK is in the single market, it would have to accept all the rules without being able to vote on them. And, as the UK’s deputy permanent representative to the EU told us, the EU 27 Governments now have a better understanding of where their own economic interests, and those of their own sectors, lie, regarding access to the UK market.

We therefore need a special and different solution, rather than simply something done before. It is in our mutual interest to get this right. For instance, the representation of the German state of Bremen told us that 10 per cent to 15 per cent of the GDP of all of Germany’s 16 states is exposed to the UK market.

The Canadian embassy told us that 70 per cent of their cross-border trade with the USA is carried by trucks, with security clearance programmes for trucks and drivers and an eManifest programme for goods, delivering, quote,

'a very efficient and speedy system'.

Turkey has a customs union agreement with the EU, whilst remaining outside the EU. Switzerland is neither in the single market nor the customs union, yet Turkey’s frontier is far more heavily policed than the Swiss one. In fact, 10 times as many people travel between Switzerland and the EU as do between the island of Ireland and the UK. Switzerland’s border is crossed by around 2.4 million people every day. Switzerland sells more than five times as much per head to the EU than Britain.

The European Parliament’s constitutional affairs committee commissioned a report, ‘Smart Border 2.0—Avoiding a Hard Border on the Island of Ireland for Customs Control and the Free Movement of Persons’, from the former director of the World Customs Organization, Lars Karlsson, who has visited 169 countries, worked in more than 120 of them and seen more than 700 borders. Published last November, this proposes a customs co-operation model, combining advanced data exchange and new technical components, including a new trusted trader programme, a new trusted traveller scheme and a different approach to security and safety. He said that

‘delivering almost frictionless borders is real, not science-fiction for the future,’ and that

‘we are not talking of massive infrastructure, like houses and border crossings.’

He also said that

‘a new generation of smart borders after Brexit would give Britain an extra advantage’ on the world stage and make the UK a ‘very attractive trading partner'.