Downing Street has apologised to the Queen for hosting two parties at No 10 the night before the Duke of Edinburgh's funeral in April 2021.
The monarch, 95, sat alone at the socially-distanced service at St George's Chapel in Windsor on 17 April and only 30 royals were able to attend Prince Philip's funeral in-person due to restrictions at the time.
Prime Minister Boris Johnson's official spokesman said on Friday: "It's deeply regrettable that this took place at a time of national mourning, and No10 has apologised to the Palace.
"You've heard from the Prime Minister this week, he's recognised No10 should be held to the highest standards and take responsibility for the things we did not get right. We have apologised to the Palace."
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It's understood the apology happened through official channels over the phone, rather than the PM speaking to the Queen directly or it being put in writing.
The monarch usually holds a weekly audience with Mr Johnson every Wednesday.
The Queen pictured with Prime Minister Boris Johnson in June 2021
The apology comes after The Telegraph reported that two leaving events took place in No10 on 16 April, at which time indoor social gatherings were banned.
An inquiry into alleged government lockdown parties is being carried out by senior civil servant, Sue Gray.
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The monarch sat alone at her husband's funeral in April 2021
The Duke of Edinburgh passed away at the age of 99 on 9 April, with his funeral taking place eight days later.
The Queen was accompanied by her lady-in-waiting, Lady Susan Hessey, as she travelled to the service, but she sat alone inside the chapel as she bid farewell to her husband of 73 years.
Other royals in attendance included the monarch's four children, Prince Charles, Princess Anne, Prince Andrew and Prince Edward, as well as her eight grandchildren and their spouses.
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