A former prime ministerial aide who arranged a bring-your-own-booze garden party during coronavirus restrictions is to receive an honour at Windsor Castle on Wednesday.

Former principal private secretary Martin Reynolds was dubbed “Party Marty” after the revelations emerged about the May 20 2020 gathering in the Number 10 garden.

Mr Reynolds will be made a Companion of the Order of Bath in an honour for public service.

The Covid-19 Bereaved Families for Justice (CBFFJ) campaign group said the honour is “an insult” to the memories of those who died, those who grieved alone in lockdown, and frontline workers who served in the pandemic.

Mr Reynolds was included on Boris Johnson’s resignation honours list which was announced in June last year.

So-called partygate cause anger among the public (Dominic Lipinski/PA)

Appearing before the UK Covid-19 Inquiry in October 2023, Mr Reynolds apologised “unreservedly” when asked about the party.

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!” it said.

He told the inquiry that he was “deeply sorry” for “my part in those events and for the email message which went out that day”.

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.

He said: “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.”

Former deputy PM Therese Coffey is among those being honoured (Danny Lawson/PA)

While many recipients agree to speak to the media after honours ceremonies, it is understood Mr Reynolds is not expected to do so.

The CBFFJ said: “The fact that Martin Reynolds is being given an honour for public service having invited staff to a bring your own booze party in No 10 during lockdown is an insult to the memories of those who died because the government failed to protect them, to all who died and grieved alone during lockdown, and to every key worker who sacrificed so much to keep people safe in the absence of a government capable of handling the crisis of Covid-19.”

The group said Mr Reynolds had “failed in serving the public”, adding that his “mistakes should cost him this honour”.

Others due to be presented with honours include former Conservative deputy prime ministers Dame Therese Coffey and Sir Oliver Dowden, both for political and public service, having been named in Rishi Sunak’s dissolution honours list in July.

The ceremony, to be led by the Princess Royal, will also see organ donation campaigner Mairtin Mac Gabhann made a Member of the Order of the British Empire (MBE).

Mr Mac Gabhann’s son Daithi inspired a change in organ donation rules in Northern Ireland.

When the honour was announced in June, Mr Mac Gabhann, from west Belfast, told the PA news agency it had not been an easy decision to accept it, but that Daithi’s campaign “has always been about something greater than any political stance”.