British racing was left reeling on Tuesday following the devastating news that crowds are unlikely to return for six months – something one of the industry's most senior figures said "threatens the survival of sports organisations and the many livelihoods they support".

The impact of the coronavirus has already had a huge impact on the sport, which has taken place behind closed doors since its resumption in June, although it was hoped spectators would be able to return from October 1.

However, that optimism disappeared when prime minister Boris Johnson, speaking in the House of Commons, announced the restrictions in a bid to curb transmission of the disease, including the banning of crowds at planned sports pilots such as Newmarket's three-day Cambridgeshire meeting this week.

"We will spare no effort in developing vaccines, treatments and new forms of mass testing but unless we palpably make progress we should assume the restrictions I've announced will remain in place for perhaps six months," Johnson said.

"If things turn around and the British public can do what they did before to get this virus under control then, of course, we will review the measures."

Those words were described as "serious blow to the horseracing industry and to the people and communities who depend upon it for their living" by the BHA, Horsemen's Group and Racecourse Association (RCA), which added in a statement: "We have told the UK government our racecourses were facing a loss of £250 to £300 million of revenues this year, which in turn means less prize-money flowing through to our participants and our owners."

Johnson's measures – which he expects to be enforced by the devolved powers in Wales and Scotland – raise the possibility of the Cheltenham Festival, the jewel in the crown of Jockey Club Racecourses, which owns 14 other tracks, going ahead with no crowd in March.

Doncaster hosted a trial for racegoers this month and Warwick, another Jockey Club venue, opened its doors to a limited number of people on Monday, but the fact the paying public could be absent for what would in effect be 12 months dating back to lockdown in the spring has resulted in calls for government intervention.

Racing post