The new prime minister may be able to renegotiate part of the document setting out future relations with the European Union, the UK’s longest serving MEP has claimed.
Veteran Labour politician David Martin said he believed European leaders would be “open to a discussion on how we might change the Political Declaration”.
But Mr Martin, who has spent 35 years as an MEP, said he could not see “any momentum” within the other 27 EU member states to go back and make changes to the formal Withdrawal Agreement.
Both Boris Johnson and Jeremy Hunt, the two men vying to succeed Theresa May as the UK’s next prime minister, have said they believe they will be able to reopen talks to try to secure a better deal for the UK.
Such claims have been dismissed by Brussels.
While Mr Martin accepted the Withdrawal Agreement – which includes backstop arrangements to prevent the return to a hard border in Ireland – would not be revisited, he said the Political Declaration could be.
This shorter document sets out what the relationship between the UK and the EU could be like in the future.
Mr Martin, speaking to PA from Strasbourg on his last full day as an MEP, said: “It is easy to predict what Brexit is going to do to the UK, it is going to diminish us as a country, it’s going to give us less influence in the world, it is going to make us less attractive for economic investment and a less outgoing country because of the loss of easy free movement across the European Union and so on.
“It is more difficult to predict what impact it is going to have here.”
He said until now the other 27 EU states had been “remarkably united” in their approach to Brexit but added: “I don’t think there is unanimity anymore.
“I think that are some member states, perhaps led by the French, who think that even a hard Brexit would do less damage than continuing the psycho-drama we’re engaged in.
“There are some countries who now just want it over like, I think sadly, a big section of the British population.
“And there are others like Chancellor Merkel, whose power is waning a little bit now … who is prepared to give Britain as long as it wishes.
“And that is also true of Donald Tusk, the president of the (European) Council, but his successor could literally be named anytime now and once his successor is named, although he will still be in office until October 31 his power will wane as well, and he has been very much been an advocate for keeping Britain in as long as possible and hoping that circumstances change.”
Mr Martin added: “If Britain goes back and says – this is a guess – we’ve got a new prime minister, a new set of proposals, we would like to sit down and negotiate it, I think Europe would still on balance say yes, even the French would say yes to that because nobody really wants a hard Brexit.
“If Britain goes back and continues to waste time, has no more proposals, I think the mood would change to say ‘let’s just end this, let’s get it over with’.”
He recalled that when he was first elected in 1984 “we literally had one fixed line telephone between three members” with a fax machine shared “between a political group of nearly 200 members”.
Mr Martin said without computers, email and Twitter “if you wanted to find out what was happening, I used to have this old longwave radio and I used to try to find a position in my hotel room or office where I could catch what was going on in the United Kingdom on Radio 4”.
Mr Martin, who was an MEP first for the Lothian region and then for Scotland, lost his seat in the European Parliament after his party slumped to fifth place north of the border in May’s European election.
He said he had been “convinced” that after the party’s poor result in the ballot, Labour would switch position and formally endorse a second referendum, as well as confirm it would campaign to Remain.
While Scottish Labour has done this, Mr Martin said that “sadly” for the party as whole “that clarity hasn’t come”.
Speaking about his time at the European Parliament, which sits in both Brussels and Strasbourg, Mr Martin cited work that gained millions of pounds of additional funding for UK coalfields via European Structural Funds in the 1980s as being “possibly the thing I am most proud of”.
He said: “It’s been a fantastic experience to be out here so I don’t feel any regrets.
“Obviously I am going to miss Brussels and Strasbourg, I’m going to miss my colleagues and friends, I’m going to miss the political activity,
“But I don’t really have any regrets, I think 35 years is a good innings for anybody.”