Allowing the St Leger horse racing festival to go ahead next month is "too great" a coronavirus risk, the mayor of Doncaster has said.
The government has included the fixture, due to begin on 9 September, in its list of sporting events used to pilot the safe return of spectators.
Doncaster mayor Ros Jones said the decision puts the coronavirus situation in the borough "in jeopardy".
Labour MP for Doncaster Central Rosie Winterton has welcomed the news.
According to the Local Democracy Reporting Service, she said she had actively lobbied the sports minister for the event to be included in the pilot.
"The St Leger Festival is a hugely important event for Doncaster and the region and, having lobbied the Sports Minister to support the bid, I am delighted that it has been approved to host a pilot event for the return of crowds," she said.
Ms Jones however said the decision was made without the input from the council.
"It is out of the control of me and the council and personally, I think the risk of Covid-19 infection is too great.
"We have been coping well in Doncaster, but this could all be put in jeopardy," she said.
The racecourse is set to welcome no more than 3,640 general admissions on its first day, rising to 6,202 general admissions for the following three days.
A new code of conduct will be in place for all attendees along with a number of additional facilities to allow racegoers to "maintain social distancing, personal hygiene and other measures".
The pilot began with the finals of the World Snooker Championships at the Crucible in Sheffield on 15-16 August.
The government has said events have been chosen to test a range of different event styles across the country's major men's and women's spectator sports.