A People's Vote rally in Parliament Square. People assemble to watch the debate in Parliament and the final vote on the Brexit deal. Barcroft Media | Getty Images

In one of the more dramatic weeks in British politics, following the defeat of Prime Minister Theresa May's Brexit agreement and her government's survival of a no-confidence vote, calls are now growing for a second Brexit referendum. Political leaders from the Scottish National Party (SNP), Wales' Plaid Cymru, the Green party and Liberal Democrats are calling on their fellow opposition party, Labour, to join them in calling for a second referendum on Brexit, known now as a "People's Vote." In an open letter to Labour leader Jeremy Corbyn following the unsuccessful vote of no confidence which he called, and which the other opposition parties had supported, the party leaders said they were writing to "implore" him to now support their calls for "a People's Vote on the final Brexit deal." Pascal Lamy, former World Trade Organization chief, told CNBC Thursday that he too believed a second referendum "is now an option." "I would not have said that six months ago and I was among those who believed that the odds of a new referendum were extremely low but I think they're clearly higher now. But of course for such a scenario to appear there has to be a 'stop the clock' between the U.K. and EU."

"I think everyone knows that either organizing a second referendum, or taking the time to reconcile the various positions which haven't been done over the last two and a half years (on Brexit) is not going to be done in one week." Following her near-defeat Wednesday evening, Theresa May invited other parties to work with her to find a way out of the impasse over Brexit. Labour said it would only do so if a no-deal scenario was ruled out. Nicola Sturgeon, the first minister of Scotland and leader of the SNP, also called on the prime minister to rule out no-deal and to consider a second referendum. Sturgeon tweet

Business leaders call for a second vote

Influential industry leaders from the U.K. retail, media and telecommunications world, among others, have also called for a second referendum on Thursday. In a letter to The Times newspaper, 130 execs said that "businesses backed the prime minister's Brexit deal despite knowing that it was far from perfect. But it is no longer an option … We urge the political leadership of both the main parties to support a People's Vote." "The only feasible way to do this is by asking the people whether they still want to leave the EU. With the clock now ticking rapidly before we are due to quit, politicians must not waste any more time on fantasies." The calls for a second Brexit referendum are now coming from current political leaders, business chiefs and former prime ministers, including Tony Blair, Gordon Brown and John Major, from across the political spectrum.