The senior aide who arranged the bring-your-own-booze garden party during coronavirus restrictions apologised “unreservedly” during an appearance at the Covid-19 Inquiry.

Former principal private secretary Martin Reynolds appeared before Lady Hallett’s inquiry on Monday, giving evidence for several hours on the atmosphere in Number 10 and the nature of decision-making at the top of Government.

Asked by lead counsel to the inquiry Hugo Keith KC about the gathering on May 20 2020, in the Number 10 garden, Mr Reynolds said he was “deeply sorry”.

But he also suggested that he did not believe it had a major impact on the public during the pandemic, given details of the event emerged in the media much later.

“I would first like to say how deeply sorry I am for my part in those events and for the email message which went out that day.

“And I would like to apologise unreservedly to all the families of all those who suffered during Covid for all the distress caused.”

He added: “It actually broke into the news about 15 months later.

“So while I totally accept, I was totally wrong in the way I sent the email around and for the event, I think the impact on public confidence, although obviously now in terms of public confidence, more generally it did have a serious impact, in terms of the pandemic at that time it was less, it had less impact.”

An email on behalf of Mr Reynolds was sent inviting about 200 staff to enjoy the “lovely weather” with some “socially distanced drinks in the garden this evening”.

“Please join us from 6pm and bring your own booze!” the email said.

Dubbed “Party Marty” after reports of the invitation emerged, Mr Reynolds was subsequently forced out amid outrage over the partygate scandal.