PIPE DREAM?
The hurdles to another referendum are high.
Both major political parties are committed to leaving the EU in accordance with the 2016 referendum.
Labour Party leader Jeremy Corbyn, who voted against membership of the European Community in a 1975 referendum, has indicated he is not keen on another referendum now.
His party has said they will only support another referendum if the deal is voted down and they fail to force a general election.
Some trade union leaders opposed another referendum because they feel it would be seen as betrayal by millions of Brexit supporters in Labour's electoral heartlands.
Brexit supporters say the 2016 vote must be respected. "It is wholly dangerous for us to turn to the people now and say, 'You let us down. You got it wrong'," said Nigel Evans, a Conservative MP.
Even if parliament did agree in principle to a second referendum, Britain would then have to ask for an extension to its timetable for leaving the EU to allow enough time for a campaign, probably by withdrawing its Article 50 departure notification.
On Tuesday, just hours before a five-day parliamentary debate on May's deal, an adviser to the European Court of Justice said Britain could revoke its formal divorce notice. The court is due to rule on Dec. 10.
Even if there was a change in mood there would be controversy about what the question would be and whether another referendum would deliver a different result.
After the failure of the 2016 campaign, pro-Europeans turned on each other and blamed what they saw as the chicanery of their opponents on the Brexit campaign.
But in the wake of their defeat, a small group of influential politicians, journalists and campaigners started to hatch a plan to keep Britain inside the club it joined in 1973.
They had to face unpalatable truths.
Their 2016 campaign had been riven with rivalry, damaged by its association with then-Prime Minister David Cameron, underperformed on social media and was cast by opponents as the voice of the establishment arguing for the status quo.
In recent months, pro-EU campaigners have been feeling more optimistic. In October, the People's Vote organised a march of almost 700,000 people through London demanding another vote.
"The tables have turned," said McGrory. "We are the underdog. We are the scrappy campaign that is doing things a bit differently."
In the last month, two ministers have resigned calling for another referendum.
Three of the four former British prime ministers still alive - John Major, Tony Blair and Gordon Brown - have also said a second referendum is the way to resolve the crisis.
The mood in the headquarters of the People's Vote in Millbank Tower close to parliament is bullish.
Young people examine charts of target audiences and organise an advertising blitz to convince lawmakers to block the government's deal.
"If anyone thinks Brexit is a done deal they should be ready for another surprise," McGrory said.
