One of Theresa May's most outspoken critics, Mark Francois, has said she was "the architect of her downfall".
But the Conservative MP acknowledged it was a "very sad occasion" as the Prime Minister fought back tears whilst announcing her resignation this morning.
"It is a tragic situation, but having called for her publicly to go I can't pretend that I didn't," he told talkRADIO's Mike Graham.
“Do I regret her going? No. I believe she had to go and believe ultimately she brought it upon herself. Do I realise that this is a very sad occasion? Yes I do."
He continued: “All the way through this process she hasn’t listened to her own party. That unfortunately is what’s led to the events of today."
Mr Francois is yet to throw his support behind one of the many high-profile MPs considering a bid for the top job, which include Boris Johnson and Esther McVey.
However the leadership group must be made up of those who “really believe in leaving”, Mr Francois said.
“The critical thing is to pick a leader who really believes in leaving in their heart and soul.
"And if they do that and appoint a cabinet that believes in leaving, then I think there’s now a better than 50 per cent chance we can leave on Halloween.”
The Liberal Democrat’s Brexit spokesman Tom Brake added that whoever takes over as leader will inherit a "poisoned chalice".
“They got completely bogged down in trying to deliver Brexit so whoever inherits this poisoned chalice is going to have exactly the same problems as the outgoing Prime Minister," he said.
“The best candidate is someone who’s going to be willing to bring together a broader coalition than just the Conservative party.”