The comments from the chain led by Tim Martin - a Brexit enthusiast and once prominent supporter of Mr Johnson - come as the prime minister faces intensifying political pressure over the gatherings in 2020.

Wetherspoons made the statement as it reported a sales hit over the Christmas period blamed on restrictions designed to halt the spread of the Omicron variant - which it has previously described as a "lockdown by stealth" - and confirmed it was heading for a half-year loss.

The pub chain used the opportunity to turn its fire on Mr Johnson - a man Mr Martin once described as a "winner" who would "make a good prime minister".

Wetherspoons said that while public anger over "partygate" was focused on hypocrisy, it had also highlighted other ramifications of lockdowns and pub closures that were in effect at the time.

In a statement it said: "If, instead of partying in No 10 on the 20 May 2020, for example, the attendees had been able to visit a pub (pubs were locked down at the time) there would have been a number of advantages for the nation."

Wetherspoons said highly trained staff at its central London pubs "would have easily dealt with the 'high jinks' alleged to have occurred at No 10".

It also said that CCTV coverage in the venues would have helped in the gathering of evidence for "subsequent enquiries".

Wetherspoons added: "In 2020, before vaccinations were available, COVID controls in pubs were superior to private parties, with screens, sanitisers, optimal seating layouts and so on.

"Wetherspoon, for example, registered over 50 million customer visits in the second half of 2020, when pubs were permitted to reopen, and there were no outbreaks of the virus among customers, as defined by the public health authorities, during this time."

The statement appeared in a trading update that focused on the impact of Plan B on the pub chain's business.

Wetherspoons has previously warned over the effect of the rules even though they did not order the closure of hospitality firms, since the guidance prompted many employees to work from home.

It said in its latest update that, as a result, like-for-like sales for the 12 weeks to 16 January fell by 15.6%.

Mr Martin said: "The company will be loss-making in the first half of the financial year, but hopes that, with the ending of restrictions, improved customer confidence and better weather, it will have a much stronger performance in the second half."

Shares, still down sharply on pre-pandemic levels, fell by a further 2% initially but closed almost 2% higher following confirmation from the government that the Plan B COVID restrictions for England were to end.