We’ve had a fair amount of talk in recent days about different kinds of Brexit.

This has been prompted by comments from Labour leader Sir Keir Starmer and erstwhile Conservative prime minister Theresa May.

Sir Keir’s u-turn on Brexit has been fascinating, as well as most disappointing. He was one of the robust and sensible voices warning of the damage it would cause back in 2019, when the House of Commons was doing a good job of saving the UK people from the costs the Brexiters wished to impose on them.

Since then, he has embraced Brexit. It has been a quite remarkable journey for Sir Keir.

The Labour leader said at the weekend, in an interview with the Financial Times in the Canadian city of Montreal, that he will seek a "much better" Brexit deal with the EU if Labour wins the next general election.

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Sir Keir, who was speaking at a conference of centre-left leaders, said of the agreement reached with the EU by former prime minister Boris Johnson: "Almost everyone recognises the deal Johnson struck is not a good deal - it's far too thin.”

Speaking as if he had won the election already, Sir Keir added: “As we go into 2025 we will attempt to get a much better deal for the UK.”

The UK’s Trade and Cooperation Agreement with the EU is due for review in 2025, with Sir Keir declaring he sees this as an “important” moment to reset relations.

The Labour leader added that he was confident a better deal could be negotiated with Brussels, as well as a "closer trading relationship…subject to further discussion”.

He declared: “We have to make it work. That's not a question of going back in. But I refuse to accept that we can't make it work.”

Sir Keir claimed he was thinking about "future generations" when he said this.

He added: "I say that as a dad. I've got a 15-year-old boy and a 12-year-old girl. I'm not going to let them grow up in a world where all I've got to say to them about their future is, it's going to be worse than it might otherwise have been.

"I've got an utter determination to make this work."

The “make it work” philosophy remains entirely unfathomable. If a foolish action is causing major damage, you should undo the mistake, to the maximum extent possible.

It would take a while for the UK to get back into the EU, even if the political will existed. However, it would be relatively simple to go back into the single market and customs union, and this could be achieved relatively quickly.

Sadly, Sir Keir reiterated his decision to rule out rejoining the customs union, the single market, or the EU in the interview with the Financial Times.

The things that Sir Keir has spoken about already in terms of improvements to the Brexit deal, while not entirely insignificant, are small potatoes. Their effects would be tiny in the context of the overall economic damage being inflicted by the loss of frictionless trade with the EU and broader European Economic Area and the ending of free movement of people between the UK and EEA.

Sir Keir has flagged a desire to strike a veterinary agreement with the EU to make border checks on animals and food less onerous. He is also looking for an agreement between the UK and EU on the recognition of professional qualifications.

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The Labour leader talked about closer ties in areas such as security, innovation and research, in the interview on the sidelines of the Global Progress Action conference in Montreal, as he declared: “I think there’s more that can be achieved across the board.”

The director of the UK in a Changing Europe think-tank, Anand Menon, warned earlier this month that Brexit’s economic impact will continue to be felt by the UK, exacerbating the country’s problems in generating growth.

Mr Menon observed, in a paper published with Full Fact, that both the Conservatives and Labour were not “anxious to make Brexit a major issue”.

Highlighting the political dimension, he said: “Labour fears alienating Leave supporters. And it is hardly easy for the Conservatives to sell the benefits of Brexit at a time when so many see it as at least partly responsible for our current economic woes.”

Mr Menon added: “Of course even were Labour to be successful in reaching, for instance, a veterinary agreement with the EU, these kinds of measure will make little difference to the overall economic impact of Brexit. Consequently, that impact will continue to be felt, exacerbating the problems in generating growth…It is anyone’s guess as to whether, and if so when, the debate over the economics of Brexit translates into serious political will to revisit some of its guiding principles.”

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Ms May, for her part, said in an interview with radio station LBC that Mr Johnson had struck a “bad” Brexit deal. This is, of course, true.

She said: “I had always said that the deal that he accepted, with that border down the Irish Sea, could not be accepted…in my view by any UK prime minister, because of the separation between Great Britain and Northern Ireland that it created.

“But he accepted what the EU had actually proposed in the first place, and then claimed it was a great victory. And on the back of that, of course, he was able to say he’d done Brexit - and on the back of aiming to get Brexit, he was able to get the very good election results.”

This is also a fair enough assessment of what happened.

Ms May meanwhile declared to the BBC that the UK would be better off if Conservative MPs had accepted her deal and moved on.

The crucial point here, however, is that the deal she had negotiated, while not as hard a Brexit as that ultimately delivered by Mr Johnson and his crew of arch-Leavers, also involved exiting the European single market and losing all the benefits of being part of the powerful bloc. And that is the crucial point.

Sadly, unless we are talking about the UK rejoining the single market, Brexit means Brexit, to use Ms May’s own words when she was prime minister. Sir Keir and Ms May were at the time of the 2016 referendum Remainers, unlike the arch-Brexiters who were so hell-bent on ripping the UK out of the EU regardless of the cost to households and businesses.

However, that is of little relevance now.

And if Sir Keir is actually concerned about future generations, and wants not to be telling people that things are much worse than they might otherwise have been, he should be promising at least re-entry to the single market, which would be an enormously positive step from where we are right now.