A leading Remain campaigner told a meeting in Watford that a People's Vote was becoming more and more likely - and said no other options are credible.

Labour peer Baron Adonis spoke to around 120 people at a meeting held by Watford For Europe at the Wellspring Church Centre on Thursday.

With the next step uncertain if Prime Minister Theresa May loses this evening's vote, and no Parliamentary majority for a "no deal" exit, he said there were two groups supporting it - those who, like him, had been campaigning since the first referendum, and others were coming round to the idea because everything was proving to be "unviable".

He said: "We cannot continue with this undecided and a massive, festering wound across our national life. The right thing to do is a referendum."

Citing a speech from 2011, he claimed leading Conservative Brexiteer Jacob Rees-Mogg MP was initially in favour of a 'dual referendum' - with a first vote on whether to enter negotiations with the EU and then on the terms of the agreement.

With the outcome after tonight's vote uncertain, he predicted a majority in Parliament for extending Article 50 to delay Brexit - and "Groundhog Day".

He said there was no Parliamentary support for a 'no deal' Brexit, and pointed to the current situation, with the Government rehearsing lorry traffic jams outside Dover.

He said it was "unbelievable" that the nation was preparing for no deal as if "it was the middle of a war".

He added: "Did we know anybody who voted for this two years ago?"

Challenged by audience member and "Tory Brexiteer" Sam Swerlinge, of Carpenders Park, who said the default legal position if no deal could be agreed was to leave without a deal, he said the March 29 departure date could be changed by the Government, with parliamentary approval.

He pointed to four main reasons to remain in Europe - jobs and economic prosperity, Ireland and the Good Friday Agreement, young people and peace in Europe - with once unstable nations such as Portugal and Estonia having benefited from joining the EU.

Speaking to the Watford Observer after the talk, he said: "There has been a big movement in public opinion as people have seen the Brexit Deal and as they realised that there isn't going to be a pot of gold that is going to pay for the NHS.

"But instead we have already agreed an exit deal of £39 billion and people are likely to lose their jobs because there is going to be less trade with Europe.

"As David Davis said, a democracy isn't a democracy if people can't change their mind, and people should have a chance to give their view on the deal."

After his speech, Lord Adonis took questions from the audience:

Francis Durham said he had left the Labour Party over Jeremy Corbyn's stance on Brexit, said Labour's "disjointed" approach needed to radically change if a People's Vote was to be successful.

One questioner suggested that he was misquoting Jacob Rees-Mogg, and asked how he could speak for people from countries such as Estonia and Portugal. She asked what he would say if there was a second referendum and Leave won.

Lord Adonis said: "If the people vote to leave once they have seen the deal, what will my position be? That we should leave."

Eddie, from Bushey, said that whatever happened on March 29, the country was going to be divided and asked how it could be reunited if the initial Referendum result were overturned.

Lord Adonis said the way to heal the country would be to heal the divisions that caused Brexit - austerity, the collapse of real wages, the divide between the south and the Midlands and North.

"We should put an end to austerity, we should stop cutting local authority budgets, we should be investing more in our education system. We should be building houses on the scale we did in the 1950s and 60s.

"Leaving the EU will make all of those problems for one fundamental reason: it will give us less money to put them right."

Charles Perry, who described himself as an "environmental and social entrepreneur", said: "What we didn't do was paint a vision of the future of Europe, about it being sustainable. The Leavers' appeal was that Europe is going to fragment and collapse."

Watford Labour Party chairman Mike Jackson said he had been quite sceptical about a second referendum after being abused and shouted at in the street while campaigning in 2016, but had changed his mind.

Lord Adonis said: "One of the failures of the last referendum was that we failed to appeal emotionally to the people who want to stay in Europe. People felt disenfranchised and left behind.

"Frankly if we have a campaign led by the Conservative Party we are going to lose. It can't be the political establishment who lead it."

He added: "There's nothing I want more than for this to be a referendum on Theresa May.

"We need a group of politicians who represent the broad spectrum of British politics.

"We need Caroline Lucas, Nicola Sturgeon, We obviously need Vince Cable. John Major. I hope that my friend Jeremy will be there. It is very likely that John McDonnell and Keir Starmer.

"We also need people who aren't just from London.

"Those of us who want to stay in the EU should not say the whole business was invalid. We should say that now we can actually see the deal, now we actually know what the terms are, the right thing for the people to do is to make a judgement on those terms."