Britain may be about to experience a "political earthquake" if the Conservatives lose their overall majority.
Only weeks ago Theresa May and the Tories were set for a majority of 150 seats, according to some polls, and followed up strongly in the local elections.
But Thursday's exit poll suggests Mrs May is on course for a "huge humiliating" by failing to even get an overall majority, ITV News Political Editor Robert Peston said.
"If the exit poll is even remotely in the right territory, it's a political earthquake," he said.
Peston added: "This looks like a minus number for them and therefore a huge, huge humiliation."
Theresa May is expected to receive a frosty reception when she meets the 1922 Committee later. But what do we know about the group?
The Prime Minister appointed her former leadership rival as Environment Secretary as she confirms her new top team.
He insisted he would be backing Theresa May as leader and has warned MPs to "calm down and get behind the Prime Minister".