"[On Thursday] there will have to be an extension… Certainly we won't be leaving the European Union on the 29th of March. And secondly we'll be bound to remain in the European Union until or unless we have a [successful] negotiation. And I think at that point we may well be going to the people for a second referendum," Ali said.
The spokesperson added that the current situation favored the idea of holding a second Brexit referendum and at the right moment in the future, the vote would seem more and more inevitable.
"We're taking it in steps, but at the moment it's all in favor, I would say, of a people's vote… But when it happens when all the other options have been rolled out, it's going to start looking increasingly inevitable," Ali said.
At the same time, Ali stressed that the time for a second public vote had not come yet and rushing the referendum could only lead to bad results.
"To ask for it [referendum] and to force a vote too early I think you can lose the vote. So that debate won't happen today and it probably won't even happen tomorrow… for anybody who wants a people's vote that is a good thing. We don't want to take that vote too early as it will focus minds potentially in the wrong way," Ali said.
The idea that the extension of the Brexit deadline was a more likely option than a disorderly withdrawal was also supported by Costas Lapavitsas, professor of economics at the School of Oriental and African Studies, University of London.
"I don't think that it is the most likely outcome that we will leave at the end of the month without a deal. I think the most likely outcome is that some kind of extension will be negotiated although everything is still on the table," Lapavitsas said.
The scholar noted, however, that if the United Kingdom was destined to crash out of the European Union without an agreement, the opposition in the face of the left-wing Labour Party would get an opportunity to propose its way of handling the consequences.
"Really the only Brexit that makes sense for me and the vast majority of people in this country is a left-Brexit. So if we left without a deal it would be possible for the left to propose a whole host of things that would shift the economy and society in the right direction," the professor said.
Unlike Ali, the scholar does not believe that a second Brexit referendum is what the country needs right now because it will not help end the stalemate over the withdrawal from the bloc even if people voted in favor of retaining EU membership.
"If you ask me, as an outside observer, I would say another election is indeed the democratic thing right now. That's what the country needs, it's clear, it's clear to me. Another referendum though, if that's what it came to, wouldn't really settle the [Brexit] question… even if it [Brexit] was reversed it wouldn't really settle it… So the country really needs an election and the Labour party is right to call for one, they are right," Lapavitsas concluded.
The updated withdrawal agreement was presented to the parliament after May secured legally binding changes to the deal as a result of negotiations in Brussels. However, opposition leader Jeremy Corbyn immediately slammed the new version of the deal as nothing even close to what the prime minister had promised to negotiate.
Meanwhile, Speaker of the UK parliament John Bercow said that the government would suggest on Thursday extending Brexit deadline up to June 30 if the lawmakers came to back the divorce agreement by March 20.