The publication of an interim report by a cross-party committee investigating whether Boris Johnson lied to MPs with his partygate denials is the latest development in the long-running saga.

There is evidence breaches of Covid rules would have been “obvious” to the former prime minister, the cross-party Privileges Committee said in its damning new report.

It follows a police investigation which resulted in 126 fines, including one for the then-prime minister, and a separate probe by Sue Gray which contributed to his downfall.

The committee’s document is intended to help Mr Johnson prepare for questioning later this month, with the scandal far from over.

Here, the PA news agency takes a look at the timeline of lockdown-busting gatherings.

– May 15 2020: Cheese and wine in the Downing Street garden

Mr Johnson was photographed sitting with his wife Carrie and staff at a table with wine and cheese in the No 10 garden.

At the time, people could not legally leave their home without a reasonable excuse and could only meet one person from another household.

– May 20 2020: Bring your own booze party

The same restrictions applied when No 10 staff gathered for a “bring your own booze” event in the Downing Street garden.

The prime minister’s principal private secretary, Martin Reynolds, emailed around 200 staff to invite them to “socially distanced drinks in the garden”.

Sue Gray’s report showed other emails issued reminders to be “mindful” of cameras leaving due to the Covid press conference – so people should not be “walking around waving bottles of wine”.

Her report said Mr Johnson attended for “around 30 minutes”, with “approximately 30-40 people in the garden”.

Mr Johnson has admitted he was there for 25 minutes but said he thought it was a “work event” to thank staff for their efforts during the pandemic.

The Metropolitan Police issued fines related to this event.

– June 18 2020: Cabinet Office leaving do

A gathering took place in No 10 and then the 70 Whitehall building to mark the departure of a No 10 private secretary.

Ms Gray’s report said: “There was excessive alcohol consumption by some individuals. One individual was sick. There was a minor altercation between two other individuals.”

At the time, gatherings of two or more people indoors and more than six outdoors were prohibited.

Police fines were issued for this gathering.

– June 19 2020: Boris Johnson’s 56th birthday

Downing Street previously admitted staff “gathered briefly” in the Cabinet Room for what was reportedly a surprise get-together for Mr Johnson organised by his now-wife Carrie.

An ally of the former prime minister, Conor Burns, said he was “ambushed with a cake” at the event.

Mr Johnson, his wife and then-chancellor Rishi Sunak received £50 fixed-penalty notices from Scotland Yard for attending the bash.

However, No 10 has denied reports that, later the same evening, family and friends were hosted upstairs to celebrate the occasion.

The law at the time banned two or more people from different households being indoors at the same time.

Ms Gray’s report said neither Mr Johnson nor Mr Sunak were aware of the event in advance, and that “those attending consumed food and drink, and some drank alcohol”.

– November 13 2020: Downing Street flat do

Carrie Johnson reportedly hosted parties in the official flat over No 11 where she and her husband lived, including one event on November 13, the night of Dominic Cummings’ acrimonious departure.

A spokesman for the Prime Minister’s wife called the claim “total nonsense”.

But reports later suggested Mr Johnson was seen heading up to the flat on the night in question, and Abba songs, including The Winner Takes It All, were heard coming from the residence.

A second national lockdown for England began on November 5.

People were ordered to stay at home during this period and different households were banned from mixing indoors or in private gardens unless in a support bubble.

Ms Gray’s report said, following the conclusion of the Met Police’s investigation, she decided it was “not appropriate or proportionate” to pursue an investigation into the events.

– November 13 2020: Leaving party for senior aide

Images published in Ms Gray’s report show Mr Johnson raising a glass while surrounded by colleagues and bottles of wine.

Days after ordering England’s second national lockdown, the pictures showed the then-prime minister giving a toast for departing communications chief Lee Cain on November 13 2020.

The Metropolitan Police issued fixed penalty notices for the event. At the time, organisers of large gatherings of more than 30 people could have been fined £10,000.

– November 13 2020: Another leaving do

Ms Gray’s report said up to 20 people gathered in the No 10 press office area to say goodbye to a special adviser, with Mr Johnson dropping in.

– December 15 2020: Online Christmas quiz in No 10

Photographs showed Mr Johnson alongside an open bottle of sparkling wine as he took part in a virtual Christmas quiz for Number 10 staff.

– December 17 2020: Cabinet Office ‘Christmas party’

Cabinet Secretary Simon Case removed himself from the inquiry into Whitehall parties, to be replaced by Ms Gray, after reports emerged of a gathering in the Cabinet Office.

It was reported that the do had been organised by a private secretary in Mr Case’s team, and that it was noted in digital calendars as “Christmas party!” and included an online quiz.

The Cabinet Office said Mr Case played no part in the event “but walked through the team’s office on the way to his own”.

Days before the event, London moved into Tier 3 of the restrictions system then in place in England, meaning the hospitality sector had to close except for takeaways, and groups of six could meet in outdoor public spaces only.

Ms Gray’s report said: “A virtual quiz took place in the Cabinet Secretary’s private office for staff who were in the office and working at home that day.

“Alcohol and food were consumed during the quiz which lasted approximately 90 minutes in total.”

The Met issued fines for this gathering.

– December 17 2020: Two No 10 leaving dos

Events were held for two departing No 10 officials on the same day. The former director-general of the Government’s Covid Taskforce, Kate Josephs, said she was “truly sorry” over leaving drinks held in the Cabinet Office.

Ms Gray’s report said Mr Johnson attended for about 15 minutes to give a speech thanking them.

The other departing official was reportedly Captain Steve Higham, one of Mr Johnson’s private secretaries.

– December 18 2020: Downing Street Christmas party

Officials and advisers reportedly made speeches, enjoyed a cheese board, drank together and exchanged secret Santa gifts.

The prime minister did not attend.

Mr Johnson’s spokeswoman, Allegra Stratton, resigned after a video emerged of her joking about a “fictional party” at a mock press conference.

Ms Gray’s report said a gathering in the No 10 press office lasted “several hours”.

“Between 20 and 45 individuals attended over the course of the evening,” it said.

She also said “some members of staff drank excessively” and cleaners later found “red wine spilled” on a wall.

At the time, indoor gatherings of two or more people from different households were prohibited.

Police fines were issued for the event.

– January 14 2021: More Downing Street leaving drinks

A gathering was held in No 10 to mark the departure of two private secretaries, with Mr Johnson attending briefly to give a speech.

The third national lockdown had kicked in on January 6, meaning people were once again told to stay at home.

– April 16 2021: Two leaving dos on the eve of the Duke of Edinburgh’s funeral

The night before the Queen sat alone at the funeral of her husband of more than 70 years, in compliance with Covid rules at the time, two leaving dos were reportedly held in No 10.

Downing Street apologised to Buckingham Palace after details emerged of boozy drinks parties, including one for outgoing communications director James Slack.

Socialising indoors with people from other households was not allowed and meeting others outdoors was limited to groups of six people or two households.

Ms Gray’s report refers to “two separate leaving events” – one for Mr Slack and another for an unnamed No 10 official.

“Alcohol was available at both events and there were speeches,” she said.

“Senior officials attended. Both groups met in the No 10 garden later that evening. The events lasted for several hours.

“The Prime Minister was not in residence.”

The police handed out fines for the event.

– November 2021

The first reports of parties emerged, followed by a series of denials from Mr Johnson, Downing Street and Cabinet ministers.

– April 12 2022

A No 10 spokeswoman confirmed that Mr Johnson and Mr Sunak would be issued with fines for breaches of Covid-19 regulations following allegations of lockdown parties in Downing Street and Whitehall.

Mr Johnson, his wife and the then-chancellor all apologised and confirmed they had paid fines imposed over a party held on June 19 2020 to mark Mr Johnson’s 56th birthday.