Drinks events were a weekly occurrence at No10 throughout the pandemic, with staff holding “wine-time Friday” regularly, according to a newspaper report.
The Mirror reported claims that Boris Johnson often attended the events and encouraged staff to “let off steam”.
This was despite Covid-19 restrictions imposing strict rules on people meeting others indoors throughout much of the pandemic.
Staff bought a £142 drinks fridge to keep bottles cool in the office, the newspaper reported.
No10 did not deny the allegations but pointed to the Sue Gray inquiry into Downing Street parties, saying its findings would be published in due course.
A No10 spokesperson said: “There is an ongoing investigation to establish the facts around the nature of gatherings, including attendance, setting and the purpose with reference to adherence to the guidance at the time.
“The findings will be made public in due course.”
The claim comes after it emerged that a suitcase allegedly used to ferry wine into a Downing Street party has been used for such purposes since at least David Cameron’s tenure in No10.
A former No10 adviser told i the suitcase had been around Downing Street for several years.
“Friday evening is always press office drinks, people put money in and someone is nominated to get the booze,” they said.
“The suitcase is the most convenient way of wheeling it all back rather than clinking in with some carrier bags.”
The bag was allegedly used for a leaving drinks event held for James Slack, the prime minister’s former director of communications, in April.
It was one of two events held at No10 on the day before Prince Philip’s funeral – where the Queen was forced to mourn alone.
Another party was organised for a second member of staff who was also leaving. Both groups joined up later in the night of 16 April 2021, with around 30 members of staff said to have been drinking and dancing, it is claimed.