The latest resignations have come from the UK education minister and the UK Northern Ireland Secretary.
It is pertinent to note that the post he has resigned from is the Conservative Party leadership. Around 1,00,000 Tories will now elect the next party leader who, after assembling a majority in the Commons, will be invited by the Queen to form a government and become the next prime minister.
While Johnson's government has been enduring the Partygate crisis for months, it was the Chris Pincher scandal that catalysed the present state of affairs.
Here are five politicians, all currently or formerly part of Johnson's Cabinet, who can replace him.
First on the list, the man who has been at the centre of attention: Former Chancellor of the Exchequer Rishi Sunak, who submitted his resignation minutes after former Health Secretary Sajid Javid (discussed subsequently) did the same.
"I am sad to be leaving Government but I have reluctantly come to the conclusion that we cannot continue like this," read Sunak's resignation letter.
He also highlighted his differences of opinion with the prime minister over the economic management in the country.
Analysts, however, say that this may be the former Chancellor's ploy to throw his hat back into the ring to become the next prime minister.
Born into an Indian family in Southampton, he was a pretty clear favourite to be Johnson's successor but the odds reduced after his economic policies failed to resolve the cost-of-living crisis in the country.
Sunak's ratings took another beating when it was revealed in April this year that his wife, Akshata Murthy, daughter of Infosys founder Narayana Murthy, held a non-domicile status in the UK.
Her non-dom status allowed her to evade millions in tax on foreign earnings via her stake in Infosys.
This did not reflect well on the chancellor, who was already under fire for failing to address the country's economic crisis.
The incumbent Minister of State for Trade Policy, Penny Mordaunt, has been a consistent critic of Prime Minister Johnson.
She has been an MP since 2010, and joined the Cabinet under Theresa May’s leadership
In last month's trust vote, she refused to reveal which way she voted but went on to say, "I didn’t choose this prime minister."
Mordaunt has been a strong supporter of Brexit and is expected to advance policies pertaining to "Global Britain" if she's elected to the top post.
Interestingly, according to a betting odds tracking website called "Oddschecker," Mordaunt is leading the race to be Johnson's successor.
Given that it was Javid's resignation letter that sent the rest of the dominoes falling, he will likely be remembered as the guy who fast-tracked the fall of Boris Johnson.
"Enough is enough," the former health secretary told the House of Commons on Wednesday.
He was also the first Muslim home secretary of the country, and also served as chancellor of the exchequer, albeit for less than a year.
A four-time Conservative party MP from Bromsgrove, Javid is a second-generation migrant belonging to a Pakistani family, who has now kickstarted one of the most serious political crises the UK has witnessed.
Allies of Javid don't know if he'll run for PM or not. One ally told the Financial Times that in his resignation speech it was "obvious that he has a pitch about reshaping the party for the future and bringing it back into line. Saj may still ultimately roll in behind someone else."
The UK government's main official with respect to the Russian invasion of Ukraine, Elizabeth Truss has been the Foreign Secretary since September last year.
She has made it clear that she is remaining loyal to Prime Minister Boris Johnson following the resignations of Sunak and Javid.
Truss has been responsible for a broad range of Cabinet responsibilities, including environment and justice, before taking on foreign affairs.
While she was not a supporter of Brexit initially, she is now one of the strongest defenders of the deal.
Lately, other than the Ukraine war, Truss has been busy with the controversy surrounding the Northern Ireland Protocol, a post-Brexit, special trading arrangements between the UK and Northern Ireland, by way of which border and document checks would occur for goods being transported between Northern Ireland and Great Britain.
You can read about in more detail here.
Truss told the BBC last month, "The majority of people in Northern Ireland believe that the protocol needs to change."
Born in Baghdad to Kurdish parents, Zahawi came to the UK as a boy, after his family fled Saddam Hussein’s Iraqi regime in the 1970s.
Nadhim Zahawi was at best a dark horse for the post of PM until Wednesday. But now, given that he is Sunak's successor, he is one of the top contenders for the top post.
Having served as the secretary of state for education, Zahawi has stood out for how he, as vaccine minister, oversaw the UK's vaccination roll-out during the COVID-19 pandemic.
One Tory told the Financial Times, "Nadhim has been working the parliamentary party hard for some time. No one is any doubt he will run and I think there’s a good chance he will win."
Apart from backing Brexit in 2016, Zahawi has also been a staunch defender of Johnson throughout Partygate.
He, however, according to AFP, told Johnson on Thursday to 'go now'.
Other than the five aforementioned politicians, there are four other possibilities as well - Chair of the Health and Social Care Select Committee Jeremy Hunt, Secretary of State for Defence Ben Wallace, Chairman of the Foreign Affairs Committee Tom Tugendhat, and Attorney General for England and Wales Suella Braverman.
(With inputs from FT, AFP and the BBC.)