In an admiring profile published in the UK's New Statesman magazine last Friday (Pedro Sánchez: Europe's left-wing icon), Pedro Sánchez said that he would "absolutely" welcome the UK back into the EU. "We miss the UK within the EU," he told journalist Adam Rasmi: "I think there is a clear need to have the UK on board again, especially nowadays."

The Spanish premier isn't alone. There's a lot of support for Britain (surely somewhat sheepishly) returning to the European fold after having left in 2020, both domestically and across the continent; but it wouldn't be a return to pre-2016 normality. Rather, the terms of re-entry would almost certainly demand a level of integration that has always been opposed within the UK and is still deeply unpopular.

A YouGov poll conducted last June found that 55% of Brits and 60% of Spaniards supported the UK rejoining the EU. That figure was also above 50% in Germany (63%), France (53%) and Italy (51%). But support for Britain returning on the old terms - i.e. staying outside the single currency and Schengen Zone - dropped to around 20% in all four continental nations. In the UK, only 36% of respondents supported rejoining the EU without the previous exemptions. The message was clear: Britain wants to retain substantial independence, but Europe would require a bigger commitment.

One wonders what other concessions the EU would squeeze from the UK if it ever tried to formally rejoin. Would it, for example, seek partial or full repayment of the €5.4 billion Brexit

Adjustment Reserve, activated by Brussels in 2020 to help member states deal with the cost of Britain's withdrawal (from which Spain received about 270 million euros)?

Approval for re-entry among the 27 member nations would need to be unanimous, but many would name their own specific conditions too. Can we really imagine Spain wasting an opportunity to extract more concessions over Gibraltar?

As an indication of how tough re-entry negotiations would be, Brussels is already seeking a so-called "Farage Clause" in the "reset" of post-Brexit relations sought by British prime minister Keir Starmer. This would commit Britain to paying compensation if any future government cancelled the terms being negotiated. "We shouldn't be surprised that the EU is playing hardball," said Anand Menon, director of UK in a Changing Europe, in a recent interview with The Guardian: "After all, they have decided that we need these agreements more than they do. As such, they will extract every last concession."

That would also be Brussels' approach if the UK were ever to come knocking at its door again. One suspects that Britain would emerge from a re-entry agreement much as the EU did after signing that trade deal with Donald Trump last summer: shafted.