Sajid Javid piled pressure on Boris Johnson to quit on Wednesday in a personal statement to the Commons on his resignation as Health Secretary.
The ex-Cabinet minister told a hushed House of Commons how he was not a “quitter” and was “instinctively a team player”, having stood by the Prime Minister during a string of controversies including the partygate scandal.
He stressed: “Institutions and integrity are both central pillars that underpin our great democracy.
“It doesn’t matter what your political perspectives are coming into this House.
“I believe we are all motivated by the national interest.
“And that the public expects all of us to maintain honesty and integrity in what we do.”
He stressed that this issue was “not an abstract matter”.
He continued: “We’ve seen in great democracies what happens when divisions are entrenched, not bridged.
“We cannot allow that to happen here - we must bring the country together as One Nation.”
He emphasised that effective governance “inevitably requires loyalty and collective responsibility” by ministers.
“But treading the tight rope between loyalty and integrity has become impossible in recent months,” he added.
“Mr Speaker, I will never risk losing my integrity.”
He also stressed that loyalty “must go both ways”.
“The events of recent months have made it increasingly difficult to be in that team,” he explained.
“It’s not fair on ministerial colleagues to go out every morning defending lines that don’t stand up and don’t hold up.
“It’s not fair on my parliamentary colleagues who bear the brunt of constituents’ dismay in their inboxes, and at the doorsteps in recent elections.
“And it’s not fair on Conservative members and voters who rightly expect better standards from the Party they have supported.”
He stressed that resigning from the Cabinet was a “difficult choice”.
But in words directed at those who had remained in Mr Johnson’s top team, he added: “Not doing something is an active decision.”
Explaining his decision, he added: “I fear that the reset button can only work so many times.
“There’s only so many times you can turn the machine off and on again before you realise there is something fundamentally wrong.
“Last month I gave the benefit of the doubt one last time.
“But I have concluded that the problem starts at the top; that it is not going to change; and that those of us in a position to do so have a responsibility to make a change.”
He insisted he had given the “benefit of the doubt” to No10 explanations about partygate.
“And now this week again we have had reason to question the truth and integrity of what we have been told,” he added, referring to the Chris Pincher “gropping scandal”.
He stressed: “At some point we have to conclude that enough is enough.
I believe that point is now.”
Mr Javid’s statement may not have been as devastating as Geoffrey Howe’s resignation speech in 1990 which helped topple Margaret Thatcher.
However, as the Prime Minister left at the end of Mr Javid’s personal statement, some MPs shouted “Bye Boris”.
Earlier, the former Health Secretary told Parliament how he had “never been one of life’s quitters”.
He stressed: “I didn’t quit when I was told that boys like me didn’t do maths.
“I didn’t quit when old school bankers said I didn’t have the right school ties.
“I didn’t quit when people in my community told me I couldn’t marry the love of my life.”
