Mr Walker made the announcement just minutes after the Conservative Party leader announced she would be stepping down.

He felt that following events in parliament on Wednesday night, the PM's resignation was "inevitable".

Mr Walker said: "I think it is very sad for Liz and those around her but I think it was becoming clear that she hadn't got the support of the parliamentary party for the platform which she was putting forward and she had already had to make significant changes.

"It is clearly not good for the party and it's not good for the country to be in this situation.

"We now need to focus on getting out of it and through it as swiftly as possible and getting a new leader in place who can command a parliamentary majority, can actually deliver on that manifesto."

Mr Walker has revealed he will be supporting former Chancellor Sunak.

"For me, the prime candidate is Rishi Sunak," he said.

"He has shown during the leadership race a command of the fact and the issues

"I think unfortunately some of his concerns that he raised about the approach that Liz and Kwasi (Kwarteng) wanted to take with the economy have been born out by the circumstances.

"I didn't speak about this earlier because I didn't want to be seen as a sore loser.

"At the end of the day, he did predict that we needed to focus on inflation first and I am hopeful that if he can set out a program to deliver that and to deliver on our 2019 manifesto, that he will be the person to bring our party together."

READ MORE: Liz Truss resigns as Prime Minister

Announcing her resignation, the Prime Minister said: "I recognise I cannot deliver the mandate on which I was elected by the Conservative Party.

"I am resigning as leader of the Conservative Party. There will be a leadership election to be completed within the next week.

"I will remain as Prime Minister until a successor has been chosen."