Boris Johnson's future as prime minister is hanging in the balance amid widespread calls for him to resign.
Allegations of lockdown-breaking social gatherings held in No 10 and other Whitehall departments have rocked Downing Street in recent weeks - and the prime minister is now facing calls from his own backbenchers to step down.
Mr Johnson has disregarded calls for his resignation, insisting that an inquiry into the allegations conducted by Sue Gray should conclude before further action is taken.
But reports suggest a number of Tory MPs have already submitted letters calling for a leadership contest to the 1922 committee, chaired by Sir Graham Brady.
If Sir Graham receives a total of 54 letters - 15 per cent of the current sitting Tory members - a Parliamentary vote on whether the PM should stay in power will be held.
So, how did we get here?
Here's some background information on the PM's position, including when he came to power, and why the previous prime minister Theresa May decided to step down making way for the current government.
When did Boris Johnson become prime minister?
Mr Johnson was voted leader of the Conservative Party following Theresa May's resignation in 2019.
In May 2019, Ms May announced she would resign as leader of the Conservatives on June 7 and would step down as prime minister once a successor had been elected.
Mr Johnson had already confirmed he would stand for leader of the Conservatives and formally launched his campaign as she stepped down.
A poll of party members published shortly afterwards showed him to be the clear front-runner and he sailed through the ballots to become one of the final two candidates alongside Jeremy Hunt.
Mr Johnson was elected leader with 66 per cent of the votes.
On July 24, the Queen accepted Ms May's resignation and appointed Mr Johnson as prime minister.
Mr Johnson later tabled a motion for an early general election to be held in December 2019 - the third general election since 2015.
Why did Theresa May resign?
Ms May's failure to secure a Brexit deal in 2019 ultimately led to her resignation.
But concerns about the strength of her leadership first emerged in 2017 after she called a snap general election to try and increase the Conservative's majority in the House ahead of the crunch Brexit negotiations.
She wanted to "strengthen her hand" ahead of negotiations with the EU, but the Tories ended up losing their majority in the Commons with their seats falling from 330 to 317.
Ms May managed to defeat a vote of no confidence in December 2018, but the following months saw her Brexit deals repeatedly rejected in Parliamentary votes.
In an emotional statement outside her Downing Street office, Ms May finally announced she was stepping down as prime minister.
She had tried to get a Brexit deal through Parliament on three separate occasions.
In her resignation speech, she admitted that "it is in the best interest of the UK for a new PM to lead that effort".
When was Boris Johnson Mayor of London?
Mr Johnson started his career as a journalist, writing and editing for titles including The Telegraph and The Spectator.
He first stood as a Conservative MP candidate in Henley and won the seat in the 2001 general election.
In July 2007, he announced his intentions to stand in the 2008 London mayoral election, which he won after recieving 43 per cent of the first preference votes.
Mr Johnson served two full terms as London mayor, before returning to Parliament as the MP for Uxbridge and South Ruislip following the 2015 general election.
He went on to serve as foreign secretary under the leadership of Theresa May.
