Two key members of Boris Johnson's have resigned, plunging the prime minister into a fresh leadership crisis.

Rishi Sunak has quit as chancellor and Sajid Javid has resigned as health secretary this evening.

Mr Sunak said “the public rightly expect government to be conducted properly, competently and seriously”, adding “I believe these standards are worth fighting for and that is why I am resigning.”

In an incendiary letter, Mr Javid said the British people “expect integrity from their government” but voters now believed Mr Johnson’s administration was neither competent nor “acting in the national interest”.

The resignations came as Mr Johnson was forced into a humiliating apology over his handling of the Chris Pincher row after it emerged he had forgotten about being told of previous allegations of “inappropriate” conduct.

Mr Pincher quit as deputy chief whip last week following claims that he groped two men at a private members’ club, but Mr Johnson was told about allegations against him as far back as 2019.

The prime minister acknowledged he should have sacked Mr Pincher when he was told about the claims against him when he was a Foreign Office minister in 2019, but instead Mr Johnson went on to appoint him to other government roles.

But other government ministers – including Therese Coffey, Suffolk Coastal MP and Work and Pensions Secretary – have stuck by the PM.

James Cartlidge, South Suffolk MP, and Rishi Sunak's Parliamentary Private Secretary (PPS) during the pandemic, tweeted following his former boss's resignation.

Mr Cartlidge, who is now a junior justice minister and an assistant government whip, wrote: "I had the privilege to be PPS to [Rishi Sunak] through the pandemic.

"I will never forget those weeks in March & April 2020 where he put heaven & earth into furlough & all the other schemes. Whatever is written about today, a lot of businesses wouldn’t be around today if not for him."

Dr Dan Poulter, Central Suffolk North Ipswich MP, said: "I very much respect the decision made by Rishi Sunak and Sajid Javid and support their commitment to upholding honesty and integrity in high public office."

Peter Aldous, Waveney MP and a critic of the prime minister, said: "I respect and acknowledge the decisions Rishi Sunak and Sajid Javid have come to. I think they were inevitable decisions because I don't think this situation could continue.

"I acknowledge and respect the prime minister's work in addressing the major problems such as Brexit, the Ukraine crisis and Covid, but we can't keep going on having these serious, major distractions every two to three weeks.

"I do hope, and I say this with sadness, that the Prime Minister takes stock of what Mr Sunak and what Mr Javid have said and steps aside in the next two to three days."

A spokesman for Matt Hancock said the West Suffolk MP and former health secretary would not comment on the resignations this evening.

This article will continue to be updated.