A “stronger and united Europe” — one with the United Kingdom still in the EU — could have been enough to dissuade Vladimir Putin from his full-scale invasion of Ukraine, according to a senior MEP.

Guy Verhofstadt, the Belgian MEP and former European Parliament  chief negotiator on Brexit, made the argument in a radio interview today on the third anniversary of the UK leaving the bloc.

Mr Verhofstadt told LBC that the “brutal invasion” by Russia “has nothing to do with the extension of Nato, it has nothing to do with … the European Union. It’s really an attempt by Putin to restore the old Soviet Union.”

He said that: “A united Europe, certainly on defenve matters, would make an enormous difference.”

He added: “I think maybe without Brexit maybe there was no invasion. I don’t know, I guess that he would see a far stronger and united Europe on the other side."

Mr Verhofstadt said he hoped that Britain will one day rejoin the bloc and that Ukraine can also join, “why not within five years?”

The former chair of the European Parliament’s Brexit steering group was among the most ardent opponents of Brexit and critics of Boris Johnson.

During the Brexit talks he often took to task Mr Johnson after the former Prime Minister repeatedly described the EU as "undemocratic".

In September 2019, he applauded the Supreme Court's decision that Mr Johnson's five week prorogation of the UK Parliament was unlawful and attacked the Prime Minister for doing so.

The MEP wrote on Twitter: “At least one big relief in the Brexit saga: the rule of law in the UK is alive and kicking. Parliaments should never be silenced in a real democracy. I never want to hear Boris Johnson or any other Brexiteer say again that the European Union is undemocratic.”

Mr Johnson said his decision to suspend Parliament was so he could introduce “a bold and ambitious domestic legislative agenda”.

Labour and the SNP said it was a bid to stifle democracy and a attempt to block parliamentary scrutiny of his Brexit deal negotiations, then ongoing. Eventually, the Supreme Court ruled the move was “unlawful, void, and of no effect”, and parliament resumed.

Nile Gardiner, a foreign policy analyst, and former aide to Margaret Thatcher dismissed Mr Verhofstadt's comments today.

He wrote on Twitter: "Monumentally stupid comments from Guy Verhofstadt. Brexit Britain has actually been the biggest opponent of Putin's Russia. The UK has always stood up to Moscow while the EU has shamelessly appeased the Russians."

During the Brexit talks Mr Verhofstadt won over independence supporters in Scotland when he said he saw no problem for an independent Scotland becoming a member of the EU.

Appearing before the Home Affairs committee in the House of Commons in 2018 he was challenged by Scottish Conservative MP Douglas Ross on comments he had made on an independent Scotland joining the EU.

Mr Ross asked: “In September 2016, you said: ‘If Scotland decides to leave the UK and become an independent state and they decide to be part of the EU, I think there is no big obstacle to do that’. Do you still support that?”

Mr Verhofstadt replied: “That is a fact. That’s a simple fact.”