Theresa May's Brexit bid roundly criticized amid calls for her time as PM to end

British Prime Minister Theresa May dug in Wednesday against a growing push by both rivals and former allies to remove her from office as her attempts to lead Britain out of the European Union appeared to be headed for a dead end.

May resisted calls to rip up her tattered Brexit blueprint and end her embattled premiership after her attempt at compromise was rejected by both her own Conservative Party and opposition lawmakers.

There was a feverish atmosphere in Parliament, as Conservative backbenchers met in private to discuss a leadership challenge and expectations were rising that May could be forced to announce her departure within hours or days.

Lawmaker Tom Tugendhat, a leading Conservative moderate, said the only chance of delivering an orderly Brexit was for May "to go — and without delay."

"She must announce her resignation after Thursday's European elections. And the Conservative Party must fast track the leadership process to replace her," he wrote in the Financial Times.

Scottish Secretary David Mundell was to meet May at 10 Downing St. later Wednesday, and there were rumours more ministers were seeking meetings to express unhappiness with her Brexit plan — and possibly urge her to quit.

May's spokesperson, James Slack, said he was "not aware of any discussions" with cabinet colleagues.

Conservative MP Steve Baker later told reporters May will campaign in European elections on Thursday before meeting with the chair of her party's 1922 committee — made up of backbench Conservative MPs — on Friday. Some had been pushing for the committee executive to change the rules over when May can be challenged for the leadership.

In the House of Commons, May received a flurry of criticism and hostile questions as she implored lawmakers to support a bill implementing Britain's departure from the EU that she plans to put to a vote in Parliament in June.

'I have compromised'

Nearly three years after British voters opted to leave the EU, May said "we need to see Brexit through, to honour the result of the referendum and to deliver the change the British people so clearly demanded."

If Parliament rejected her deal, she said, "all we have before us is division and deadlock."

That could serve as a fair summary of Britain's current situation.

Lawmakers have already rejected May's divorce deal with the 27 other EU countries on three occasions, and Britain's long-scheduled departure date of March 29 passed with the country still in the bloc.

In a last-ditch bid to secure support for her Brexit plan, May on Tuesday announced concessions including a promise to give Parliament a vote on whether to hold a new referendum on Britain's EU membership — something she has long ruled out.

"I have compromised. Now I ask you to compromise too," she said.

That led, a few hours later, to the resignation of the pro-Brexit government House leader, Andrea Leadsom, who said in her resignation letter that she does not believe the U.K. will ever be truly sovereign under May's new deal.

And there was little sign among other lawmakers either that her plea was being heeded. Pro-EU and pro-Brexit lawmakers have only hardened their positions during months of political trench warfare, and they are in no mood to compromise.

Pro-Brexit Conservatives accused May of capitulating to pro-EU demands, and opposition Labour Party lawmakers dismissed her offer as too little, too late.

"The rhetoric may have changed, but the deal has not," said Labour leader Jeremy Corbyn. "She did not seek a compromise until after she had missed her own deadline to leave, and by the time she finally did, she had lost the authority to deliver."

Northern Ireland's Democratic Unionist Party, which props up May's minority government, said the "fatal flaws" of her original deal remained. They fear the divorce deal could see Northern Ireland split from the rest of the United Kingdom.

May's authority as Conservative leader has been shredded by her loss of the party's parliamentary majority in a 2017 election and her failure to lead Britain out of the EU as promised.

The party's powerful anti-EU wing wants to oust May and replace her with a staunch Brexit supporter.

May has said she will announce a timetable for her departure once Parliament has voted on her Brexit bill. But with defeat of that bill looking highly likely, a growing number of Conservatives are pressing her to cancel the vote and quit even sooner.

'Let's have somebody who has a clean sheet'

May survived a no-confidence vote among Conservative lawmakers in December, leaving her safe from challenge for 12 months under party rules.

Brexit-backing lawmaker Nigel Evans said he would urge the party committee that oversees leadership contests to change the rules when it meets Wednesday so that May can face a new challenge within days.

"There is a growing discontent with the way Theresa May has handled this," Evans said.

"Let's have somebody who has a clean sheet and will be able to reboot the [Brexit] negotiations."

Pressure on May is likely to increase when results come in from this week's European Parliament elections, in which the Conservatives expect to receive a drubbing.

Many British voters on both sides of the Brexit debate look set to use the election to the EU legislature to express displeasure over the country's political gridlock. Opinion polls show strong support for the single-issue Brexit Party — largely from angry former Conservative voters — and for pro-EU parties including the Liberal Democrats and the Greens.

The election is being held Thursday in Britain, but results won't be announced until all 28 EU countries have finished voting late Sunday.

May indicated she would try to battle on. She said the Brexit withdrawal bill would be published Friday so lawmakers can study it.

Despite speculation that May will scrap plans to bring it to a vote to avoid a crushing defeat, Downing Street said a vote will be held during the week of June 3.

"In time, another prime minister will be standing at this despatch box," May told lawmakers, acknowledging her days in the job are numbered.

But, she told Parliament, "in the end our job in this House is to take decisions, not to duck them.

"So I will put those decisions to this House. Because that is my duty and because it is the only way that we can deliver Brexit."