Johnson is photographed with then-fiancée Carrie Symonds and two others seated at a table. On the table are bottles of wine and a cheeseboard.
Four other members of staff are sat around a second table. Nine people are then gathered closely together around a table on the grass, with another two sat on the ground nearby.
Social distancing restrictions at the time meant that mixing between households was limited to two people, who could only meet outdoors and at a distance of at least two meters (6.5 feet). In workplaces, guidance said in-person meetings should only take place if “absolutely necessary.”
On Sunday, a Downing Street spokesperson responded to the image, saying, “As we said last week, work meetings often take place in the Downing Street garden in the summer months. On this occasion there were staff meetings following a No. 10 press conference.”
“Downing Street is the Prime Minister’s home as well as his workplace. The Prime Minister’s wife lives in No. 10 and therefore also legitimately uses the garden.”
Johnson has insisted that he believes no rules were broken, and has asked one of his top civil servants to investigate the alleged parties.
Following the emergence of the latest photograph, Labour Deputy Leader Angela Rayner tweeted: “Enough is enough. Tell us the truth about what was going on in Downing Street from the very beginning immediately @BorisJohnson.”
Senior civil servant Sue Gray has been tasked with investigating the reports after Cabinet Secretary Simon Case was removed from the probe after it was revealed he had known about a quiz held in his department.
CNN’s Luke McGee contributed.