When Iceland voted not to reopen accession talks with the EU in August, that was that. Both sides accepted the result, and the conversation moved on to more immediate matters, such as the cost of living, genealogy and whether Emmessis or Kjoris sold the better ice cream.

In Britain, despite our vastly larger economy, we can’t seem to let the EU go.

A decade after our referendum a large minority remains stuck in 2016. It is to this minority that Andy Burnham addresses himself when he describes rejoining the single market or customs union or ‘going all the way’ (an oddly coy phrase) as ‘options to be considered’.

Plot spoiler: Britain is not going to rejoin the EU.

Yes, polls currently show that voters don’t much like Brexit, but polls currently show that voters don’t much like anything.

By far the biggest advantage Remain enjoyed in 2016 was the status quo bias. Voters are change-averse, and referendums almost always see a swing to the anti-change option during the campaign. A vote to  the European Economic Community in 1972 would have gone against membership; the vote to stay three years later went in favour. 

Burnham knows that a new referendum would consume his government’s energies for years and would almost certainly end in a ‘No’ vote. But he also knows that Rejoin is hugely popular among the voters whose support he needs: 79 per cent of Labour supporters, 78 per cent of Lib Dems and 81 per cent of Greens want to go back in.

Those numbers would not survive an actual referendum, or even the announcement of one. The prospect of a vote would make us focus on what is happening in the EU.

All its flaws and misdeeds would again fill our headlines. We would hear about the economic crisis in Germany, about immigration flows in the Mediterranean, about the lack of democracy and the high-handed treatment of dissident states. And we would hear – oh, boy, would we hear – about the sleaze and corruption.

How many Britons are even aware of the 2022 banknotes scandal, which saw MEPs arrested after Belgian police found over a million euros in their homes, apparently to be distributed as bribes on behalf of Arab governments?

Britain had left, so a story that would have dominated our news for weeks was of little concern. If a new referendum was in prospect, such stories would come rushing back.

I suspect the PM knows all this. But saying so would dash his plan to lead a united Left into the next election against a divided Right – the opposite of what has happened at every poll since the 1981 Labour split.

Burnham has to keep the Euro-dream alive. He might even, depending on the opinion polls, put rejoining in his next manifesto.

There is no constitutional objection to a political party contesting an election on a pro-EU manifesto. The trouble is that it will reopen a lot of arguments and stir up a lot of acrimony to no useful end.

Quite apart from reviving the nasty culture wars that followed the 2016 poll, the prospect of renewed membership would be a distraction from necessary economic reforms.

Efforts that should go into reducing the benefits bill, facilitating the building of new infrastructure or making the NHS more patient-friendly would be frittered away on referendum preparations.

Worse, the possibility of EU membership would halt several reforms. Britain is currently third in the world when it comes to developing AI – a long way behind the US and China, it is true, but third nonetheless. That would end if we had to adopt the EU’s restrictions on the technology. 

The same is true of countless other areas where we have diverged, from targeted agricultural support to gene editing, from lifting the cap on bankers’ bonuses to freeports.

Rejoining would mean big changes, such as massive budget contributions, and small, irritating ones, such as lowering the £100 contactless limit to ¤50. It would also, ironically, require Labour to stop taxing school fees.

The biggest impact, though, would be on our trade. Being in the EU customs union – which transfers sovereignty over trade policy to Brussels – would mean scrapping every deal we have signed since we left: Australia, India, Japan, the Gulf states, the lot. At a time when the Pacific trade nexus, the CPTPP, is growing, and when countries from Indonesia to Costa Rica, from Taiwan to Ecuador, are applying to join Britain in it, EU membership would force us to quit.

We would not actually have to join to suffer these malign effects. The very prospect of re-entry would put a freeze on any useful developments. Who would want to join the CPTPP until they knew the full terms – ie, whether Britain was still there? Who would invest in technology for precision plant breeding when it might be outlawed?

There are plenty of sensible improvements to be made in our relationship with the EU. We could look at mutual recognition of professional qualifications, facilitated customs procedures, a deal on food exports modelled on the EU-New Zealand deal, a common energy grid.

None of these would represent a concession by one side to the other; all would be mutually beneficial. But the EU will not countenance them as long as it thinks that Britain might either join fully or – better from the EU’s point of view and worse from Britain’s – join the customs union.

I have often scratched my head at the bizarre Europhile enthusiasm for the customs union. As the strongly Rejoin Labour MP Stella Creasy pointed out recently, it does not mean the lifting of customs checks; it simply means the abandonment of trade deals.

While there is a case for participating in elements of the single market a la Suisse, in other words accepting common standards for some products, there is no case for the customs union – something that no one in Norway or Switzerland seriously wants to join. Why, then, does Burnham mention it? Why do the Lib Dems keep clamouring for membership? Do they not understand the difference between the customs union and the single market? Do they like the word ‘union’ and dislike ‘market’? Are they trying to wind up the Eurosceptic gammons? Or do they see it as a way to full membership – which is what it has been for every other country? 

Who can say? But as long as Eurocrats think we intend to rejoin, they will not move on sensible bilateral deals. They will doubtless try to entice us in by, for example, dropping the requirement that we join the euro; but they will have no incentive to improve our current relations, even in ways that are mutually beneficial.

Equally, as long as the possibility is hanging over us, other nations including the US are reluctant to negotiate ambitious trade accords with us.

These other countries are where the economic action is. The EU is a growth blackspot, pining for the figures the US, let alone developing states, take for granted.

Remainers used to talk about the EU taking ‘half our exports’. Even then, the figure had fallen in the previous decade from 54 to 43 per cent. It has declined steadily since. Where will it be in 20 years?

There is something terribly about the EU, a 1950s solution to a 1930s problem. Our opportunities are across the oceans. But we will seize them only when we stop obsessing over our relationship with our fastest-dwindling market.