(CNN) - An embattled Theresa May vowed to fight on as UK Prime Minister Thursday in the face of intense opposition to her troubled Brexit deal, facing down a wave of resignations and demands for her to step down as leader.
In a defiant statement at 10 Downing Street, May said her Brexit deal -- which has attracted intense criticism from all sides -- was in the national interest and made it clear that she had no intention of stepping aside.
"I believe with every fiber of my being that the course I have set out is the right one for our country and all our people," she said.
Her statement came after seven members of her government resigned, declaring they could not support the draft Brexit agreement she had struck with the European Union this week. Conservative MPs lined up to declare that they had submitted letters to party officials demanding a vote of confidence in her leadership.
In the face of this wall of opposition, May stood firm. "I do not judge harshly those of my colleagues who seek to do the same for to reach a different conclusion, they must do what they believe to be right. Just as I do, I'm sorry that they've chosen to leave the government and I thank them for their service," she said.
Brexit Secretary Dominic Raab, who has been leading Brexit negotiations with the EU, was the first Cabinet minister to quit, followed quickly by Brexit-backing Work and Pensions Secretary Esther McVey. Two junior ministers, two ministerial aides and a vice-chair of the Conservative Party also resigned.
Asked whether she was prepared to risk a split in her government as divisions in her party mount, May said that she felt MPs would honor the will of the British people when it came down to a vote.
"MPs have been debating how best to deliver on the result of the referendum ever since the result of the referendum took place in 2016. And there's been much criticism in that time of the government's approach," May said.
"But one simple fact remains and that is that nobody has produced any alternative proposal which both delivers on the referendum and also ensures that there's no hard border between Northern Ireland and Ireland," she added.
While she said she shared some concerns about the details of the backstop agreement, an inescapable fact remains: there is no deal which can be agreed with the European Union that doesn't involve an insurance policy against a return to the borders of the past in Northern Ireland.
The European Union wants the UK to agree a "backstop" or fallback position that would ensure an open border between Northern Ireland, which will be outside the EU, and the Republic of Ireland, which will remain an EU member state.
Earlier, May had endured a grueling appearance in the House of Commons as she sought to defend the deal agreed by her Cabinet just a day earlier. During a three-hour debate, May faced sustained opposition from all sides.
Labour Party leader Jeremy Corbyn slammed what he called a "botched" and "half-baked" deal, saying it "represents a huge and damaging failure" on the part of a government "in chaos."
"The government simply cannot put to Parliament this half-baked deal that both the Brexit Secretary and his predecessor have rejected," he said.
Nigel Dodds, deputy leader of Northern Ireland's Democratic Unionist Party -- which May relies on to prop up her minority government -- was also damning in his assessment of the deal, saying the Prime Minister "clearly doesn't listen."
Meanwhile, Conservative MP Jacob Rees-Mogg, who heads the influential pro-Brexit European Research Group, openly asked May why he should not demand her resignation.
He said May had pledged that the UK would leave the Customs Union, that she would maintain the integrity of the UK and that it would leave the jurisdiction of the European Court of Justice -- but that the deal did none of those things.
May had barely left the chamber when Rees-Mogg announced publicly that he was submitting a letter of no-confidence in May -- essentially an open call for the Prime Minister's own party to unseat her. A chorus of other Brexiteers have joined Rees-Mogg in calling for a vote of no-confidence.
If 48 such letters are sent to Graham Brady, the party official who represents the interests of Conservative MPs, a leadership contest would be triggered.
But in order to actually defeat May, her opponents would require 159 Conservative MPs from a total of 316 to vote against her in a simple majority vote.
Asked Thursday evening whether she would fight a confidence vote, May swiped at her critics, saying her draft deal was in the national interest, not her own political interest.
"Leadership is about taking the right decisions, not the easy ones," May said.
"As Prime Minister my job is to bring back a deal that delivers on the vote of the British people. I believe this is a deal which does deliver that, which is in the national interest and am I going to see this through."
The-CNN-Wire ™ & © 2019 Cable News Network, Inc., a Time Warner Company. All rights reserved.