Downing Street has apologised to Buckingham Palace for two staff parties in No 10 the night before Prince Philip’s funeral.
The gatherings, first reported by The Telegraph, took place on 16 April 2021 and went on until the early hours.
The PM’s spokesman said it was “deeply regrettable that this took place at a time of national mourning”.
Boris Johnson was not at either party – but he faces questions over alleged Covid rule-breaking at No 10.
The latest party revelations led to a backlash from opposition parties, who contrasted the behaviour of No 10 staff with pictures of the Queen sitting alone at the Duke of Edinburgh’s funeral, due to Covid restrictions.
The two staff get-togethers, on 16 April last year, took place at a time when Covid restrictions banned indoor mixing.
They have been added to the list of parties in government buildings being investigated by senior civil servant Sue Gray.
After the apology, Labour leader Sir Keir Starmer said: “This shows just how seriously Boris Johnson has degraded the office of prime minister.
“The Conservatives have let Britain down. An apology isn’t the only thing the prime minister should be offering the palace today.
“Boris Johnson should do the decent thing and resign.”