Sajid Javid quit his Government role minutes after Boris Johnson apologised for the Chris Pincher scandal.
The former Health Secretary said he can no longer continue his position "in good conscience", but said the public have concluded we are no longer "popular or competent".
Here is Mr Javid's resignation letter to Boris Johnson in full:
I have spoken to the Prime Minister to tender my resignation as Secretary of State for Health & Social Care. It has been an enormous privilege to serve in this role, but I regret that I can no longer continue in good conscience.
It was a privilege to have been asked to come back into Government to serve as Secretary of State for Health & Social Care at such a critical time for our country.
I have given every ounce of energy to this task, and am incredibly proud of what we have achieved. The UK has led the world in learning to live with Covid.
Thanks to the amazing rollout of our booster programme, investment in treatments, and innovations in the way we deliver healthcare, the British people have enjoyed months more freedom than other comparable countries.
We have also made important strides in the recovery and reform of NHS and adult social care. The longest waits are down by 70% and, as you know, I have been working hard on wider modernisation of the NHS.
I have also developed radical new approaches to dementia, cancer and mental health, and prepared the Health Disparities White Paper which will set out plans to level up health outcomes for communities that have been left behind for too long.
Given the unprecedented scale of the challenges in health and social care, it has been my instinct to continue focusing on this important work.
So it is with enormous regret that I must tell you that I can no longer, in good conscience, continue serving in this Government.
I am instinctively a team player but the British people also rightly expect integrity from their Government.
The tone you set as a leader, and the values you represent, reflect on your colleagues, your party and ultimately the country.
Conservatives at their best are seen as hard-headed decision-makers, guided by strong values.
We may not have always been popular, but we have been competent in acting in the national interest. Sadly, in the current circumstances, the public are concluding that we are now neither.
The vote of confidence last month showed that a large number of our colleagues agree. It was a moment for humility, grip and new direction.
I regret to say, however, that it is clear to me that this situation will not change under your leadership - and you have therefore lost my confidence too.
It is three years since you entered Downing Street. You will forever be credited with seeing off the threat of Corbynism, and breaking the deadlock on Brexit. You have shone a very welcome light on the regional disparities in our country, an agenda that will continue to define our politics. These are commendable legacies in unprecedented times.
But the country needs a strong and principled Conservative Party, and the Party is bigger than any one individual.
I served you loyally and as a friend, but we all serve the country first.
When made to choose between those loyalties there can only be one answer.
Finally, I would like to put on record my thanks to ministerial and departmental colleagues, my admiration for NHS and social care staff, and my love for my family who have been immensely patient in these challenging times.
