Momentum is building towards a second Brexit referendum with the holding of what might well be the largest rally in British history, while Prime Minister Theresa May will likely be ousted from her job this week following a revolt against her from within her own party.

Over a million frustrated and angry Britons took to the streets of London Saturday demanding a new referendum finally and absolutely settle the question of Brexit that continues to elude any solution in Parliament.

The massive "Put It To The People" called by Remainers converged in front of Parliament. Some ralliers carried European Union (EU) flags and signs calling for any Brexit deal be put to another referendum. In addition, a petition calling for a second referendum has received more than two million signatures - and counting.

This "very British protest march" was emblazoned by quite creative homemade placards. One of these read "Never gonna give EU up" while another carried the message, "Forget the Ides of March -- beware the Brexit of May." And there was a placard close to the heart of every Remainer: "Brexit is treason." Some described the march as a delightful carnival.

Marchers called for a "proper vote" this time around and said they'd been "sold down the river" during the first Brexit referendum on June 23, 2016.

Speakers at the rally included Labour deputy leader Tom Watson, Scotland's First Minister Nicola Sturgeon, and London Mayor Sadiq Khan, among others.

Labour's Tom Watson told the crowd May's deal was a "lousy" one -- whether you voted Leave or Remain. He said he had this message for May: "I can only vote for a deal if you let the people vote on it too. Prime Minister, you've lost control of this process, you're plunging the country into chaos, let the people take control."

Sturgeon said now was "the moment of maximum opportunity" to avoid a no-deal Brexit.

The more than one million people who took part in the march placed it on equal footing with the biggest British march to date, the Stop the War march in 2003.

The march came two days after the EU agreed to extend the original Brexit deadline of March 29 to May 22, which is the day before the EU Parliament elections. But there is a catch to the new EU deadline. The May 22 deadline only holds if British MPs approve the withdrawal agreement next week. If MPs junk the deal, the EU will agree to a shorter delay until April 12.

In a letter to MPs on Friday, however, Prime Minister Theresa May hinted she might not bring her Brexit deal back to the House of Commons for a third time this week if there isn't enough support for it to be passed. Complicated and confusing, as usual.

"If it appears there is not sufficient support to bring the deal back next week, or the House rejects it again, we can ask for another extension before April 12 -- but that will involve holding European Parliament elections," she tweeted.

May's effort to exit the UK from the EU, however, might no longer be her concern. At least 11 of her Cabinet ministers are demanding her ouster as prime minister, reported The Sunday Times. May voted to Remain in the EU.

The Sunday Times cited 11 unidentified senior ministers as agreeing the prime minister should stand down. They said May has become a toxic and erratic figure whose judgment has "gone haywire."

"The end is nigh. She will be gone in 10 days," said the Sunday Times quoting an unidentified minister.

"Her judgment has started to go haywire. You can't be a member of the Cabinet who just puts your head in the sand," said a second unidentified minister.

May's de facto deputy, David Lidington, is a contender to be interim prime minister, as is Environment Secretary Michael Gove and Foreign Secretary Jeremy Hunt.

The newspaper said Cabinet ministers will confront May on Monday. If she refuses to go, ministers will threaten to resign.