She offered to quit to get her maligned Brexit deal passed.
A last ditch attempt to persuade Eurosceptics to finally break the parliamentary deadlock.
So who could replace Theresa May as the next prime minister of Britain?
Here are some of the options.
First up - Michael Gove.
Leading candidate with the bookies with a 22 per cent chance of being crowned PM.
He failed in a leadership bid against May in 2016.
But has since backed her Brexit strategy.
Could this be his chance to get one up?
Another option - Boris Johnson.
Former foreign minister and May's most outspoken critic over Brexit - who resigned her cabinet in protest.
Best known for his disheveled blond hair and eccentric turns of phrase, he was seen by many as the face of the 2016 Brexit campaign.
Next, David Lidington.
May's de-facto deputy and a Remainer.
Touted as a possible interim leader - he now says he's been cured of any "lingering shred of ambition" to lead the country.
What about Jeremy Hunt?
Current foreign minister who voted to stay in the EU.
Probably best known for his run-in with the financially-stretched National Health Service while he oversaw it.
Then of course there is Jacob Rees-Mogg.
Father of six.
Flamboyant millionaire who cultivates the image of an English gentleman from days gone by.
Head of the influential ERG eurosceptic group, questions remain over whether he actually wants the job.
Next up, Dominic Raab.
The former Brexit minister quit May's government last year after just five months in protest at her draft exit deal.
When asked if he would like the Prime Minister's job, the black belt in karate responded "Never say never." There is Sajid Javid, former banker and champion of free markets.
A second-generation immigrant of Pakistani heritage, he has a portrait of Margaret Thatcher on his office wall.
No women currently topping the list.
But still in with a chance - Andrea Leadsom, a leave campaigner who made it to the last two in the 2016 contest, only to withdraw from the race.
She currently runs parliamentary business for the government.
And Amber Rudd.
Former interior minister.
She resigned following indignation over her department's treatment of some long-term Caribbean residents, wrongly labeled illegal immigrants.
If May's deal were to pass, her office has said there would be a contest to replace her after May 22, when Britain would leave the EU.
She would become the fourth Conservative prime minister in a row to have fallen foul of divisions over Europe within her centuries-old party - after David Cameron, John Major and Margaret Thatcher.