Opposition MPs and transparency campaigners called on House of Commons authorities to examine the Conservative MP’s late declaration.

“Declaring financial benefits is an important part of holding our representatives to account and should be taken seriously by members of Parliament,” said Steve Goodrich, head of research at Transparency International told openDemocracy.

“Failing to do so, especially when the amounts involved are not insubstantial, should not be ignored by the House authorities."

Robertson said that the late declaration was a lapse owing to the pandemic response. “Perhaps I was momentarily distracted by the duty upon me to help my constituents,” he told openDemocracy.

'One of racing’s staunchest allies in parliament’

Concerns have been raised that Cheltenham – a major event in the betting and racing calendar – may have helped spread the coronavirus across Britain and Ireland.

Earlier this week, chancellor Rishi Sunak defended the decision to allow Cheltenham – which attracted around a quarter of a million people – and other major sporting events to go ahead at the start of the pandemic outbreak.

The Cheltenham Festival ran from Tuesday, March 10 to Friday, March 13. A national lockdown was announced by Boris Johnson on March 23.

Five days before the festival began, Laurence Robertson posted an update on Facebook supporting the decision to hold the event.

“The disruption to people’s lives, and the risk to their livelihoods, caused by cancelling events and activities would be too great to justify [cancelling] at the moment,” Robertson wrote, citing the support of the Chief Medical Officer and government ministers’ support for allowing the festival to go ahead.

On the first day of the festival Robertson and his wife received £600 worth of hospitality from the Jockey Club, according to the register of members interests. Billed as the largest commercial horse racing organisation in the United Kingdom, the Jockey Club owns 15 of Britain's famous racecourses, including Aintree, Cheltenham and Epsom Downs.

On March 11, Robertson and his wife received hospitality valued at approximately £1,600 from bookmakers William Hill. The following day GVC Holdings covered hospitality worth £900.

On the final day of the festival, the Betting and Gaming Council supplied £900 worth of hospitality to Robertson and his wife. There is no indication of what any of this hospitality consisted of.

The MPs’ code of conduct states that all interests have to be declared within 28 days.

According to the register of MPs interests, Robertson registered the Cheltenham hospitality on April 14, more than a month after the event.

Robertson told openDemocracy that he registered the hospitality with Commons authorities on April 9, which would have meant that only the first two days hospitality at Cheltenham were registered late.