Boris Johnson said he was giving up the "best job in the world" as he announced he was resigning as Conservative Party leader in a lunchtime address today in Downing Street.

Mr Johnson said it was clearly now the will of the parliamentary Conservative Party that there should be a new leader of the party and therefore a new Prime Minister.

He said he process of choosing that new leader would begin now and the timetable should begin next week.

"I regret to not be successful in arguments and it's painful not to see through so many ideas and projects," he said.

Mr Johnson said it was preposterous to change governments - rejecting the idea of a general election - when we're "delivering so much and such vast mandates, when the economic scene is so difficult domestically and internationally".

"We must keep levelling up, keep unleashing the potential of every part of the United Kingdom," he said. "If we can do that we will be the most prosperous in Europe.

"Being Prime Minister is an education in itself - I've travelled to every part of UK and I've found so many people possessed of such boundless British originality and so willing to tackle old problems in new ways."

He added: "Even if things can sometimes seem dark now, our future together is golden."

Mr Johnson said that in politics, no one is indespensible

"I'm sad to be giving up the best job in the world. But them's the breaks."

The Prime Minister finished his statement by saying that until his replacement is found, the public's interests will be served.

The day begun with Gloucester MP Richard Graham stepping away from Boris Johnson shoirtly before the news broke that the PM was set to step down as leader of the Conservative Party.

Mr Graham announced live on BBC Radio Gloucestershire's breakfast show that he was resigning as the longest serving Trade Envoy, having served three Prime Ministers.

Yesterday, Cheltenham MP Alex Chalk resigned as Solicitor General 

This morning, he was joined by Mr Graham who said: "Sadly, things have got to the stage where is it no longer possible to just wait for everything to happen and things to resolve themselives because it's clear the Prime Minister won't do the decent thing which is accept, sadly, that the game is over and therefore all of us have a duty to explain to him that we cannot put up with this and that's why my resignation letter will be put out in half an hour's time."

In his resignation letter, Mr Graham said: "It is vital to have full confidence in the leadership and integrity of the government that I represent, and to be able to defend a government making difficult choices to my constituents in Gloucester."

Forest of Dean MP Mark Harper, a former Chief Whip and a long-standing critic of Mr Johnson, said before Mr Johnson's resignation: "The Prime Minister just has to accept enough is enough. He needs to realise reality. I think we should remember who we work for - we work for the voters and many people will be worried about the economy, paying the bills and important things in their own lives. They want a government that is competent and serious and focuses on them.

Mr Harper added: "His legacy will be assured. He's done some big things - he did get Brexit done, he won that election he did steer the country through Covid and get us through the other side but he's not the man for the future."

Cotswold MP Geoffrey Clifton-Brown, a senior Tory backbencher, said before Mr Johnson's resignation that he hoped the PM should resign and that Deputy Prime Minister Dominic Raab should become caretaker PM to encourage ministers who had resigned to continue in caretaker roles within the government.