• British Chancellor of the Exchequer Rishi Sunak resigned Tuesday, saying the government should be run "properly, competently and seriously."
• Health Secretary Sajid Javid also handed in his resignation in what appears to be a protest against Prime Minister Boris Johnson's leadership.
• Later on Tuesday evening, Johnson named Nadhim Zahawi, the former education secretary, as Britain's new finance minister. Steve Barclay was appointed as health minister.

LONDON — Two senior U.K. cabinet ministers resigned on Tuesday in protest over Prime Minister Boris Johnson's leadership, following a string of scandals that have plagued his tenure over the last few months.

British Finance Minister Rishi Sunak, in his resignation letter, said the government should be run "properly, competently and seriously." Health Secretary Sajid Javid also resigned in protest of Johnson's leadership.

The British pound hit a fresh March 2020 low after the announcements. The currency was down 1.5% for the session, hitting 1.1923 against the dollar.

Sunak said in a Tweet that "he public rightly expect government to be conducted properly, competently and seriously. "I recognise this may be my last ministerial job, but I believe these standards are worth fighting for and that is why I am resigning," he said.

In a letter to the prime minister, Sunak added, "I am sad to be leaving government but I have reluctantly come to the conclusion that we cannot continue like this."

A slew of private secretaries also resigned on Tuesday night, as well as Solicitor General Alex Chalk. Chalk said the ability of "Number 10," shorthand for 10 Downing Street where Johnson's offices and residence are located, "to uphold the standards of candour expected of the British government has irretrievably broken down," according to his resignation letter, which was shared on Twitter.

Later on Tuesday evening, Johnson made Nadhim Zahawi, the former education secretary, Britain's new finance minister. Steve Barclay was appointed health minister.

In letters to Sunak and Javid, Johnson said he was sorry to see them resign.

The prime minister narrowly survived a vote of confidence — triggered by his own lawmakers — last month. But dissatisfaction with his leadership, both within his own Conservative Party and beyond, has continued.

Johnson has repeatedly resisted calls to resign from across the political spectrum, despite sustained public anger over a long and growing list of accusations.

The latest scandal to erupt at Downing Street surrounds Conservative lawmaker Chris Pincher. The former deputy chief whip was suspended last week amid accusations that he drunkenly groped two men at a private members club.

Johnson on Tuesday evening, just minutes before the resignations, apologized for appointing Pincher as deputy chief whip — a senior party role — despite knowing of an investigation into his behavior in 2019.

Meanwhile in May, a damning report into several high-profile Covid-19 lockdown-breaking parties, dubbed "partygate," at Johnson's office and residence was released, adding to calls for the prime minister's resignation.

In a letter to Johnson published Tuesday, Javid said the recent vote of confidence was a "moment for humility, grip and a 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," he added.

— CNBC's Sam Meredith and Holly Ellyatt contributed to this report