Runners have been withdrawn by several trainers from racing at Leicester after Tuesday's meeting was cleared to go ahead despite new city lockdown rules.
The nine-race evening fixture is taking place after consultation between local health authorities and the British Horseracing Authority (BHA).
But local trainer Mick Appleby said: "I cannot believe racing is still going ahead.
"For the safety of all my staff, I have decided to withdraw all my runners."
The meeting is taking place without spectators and with safety and social distancing protocols in place.
"We feel as though we are probably the safest place in Leicester," said the racecourse's general manager David Maykels.
Starting stalls will not be used because of staffing issues - all but four of the required stalls handlers refused to work at the meeting.
It means that horses will not run according to their advertised draws, which can be a key element in studying form for punters.
A spokesperson for stalls operators Racetech told the BBC: "We received notification from a number of our stalls handlers stating they felt uncomfortable working at the course this evening.
"Unfortunately, due to the late notice, there was not sufficient time available to find replacement handlers to make up the team of 11 in time and therefore operate the starting stalls safely.
"Following a stewards' enquiry and in co-operation with the BHA and Leicester Racecourse - the decision was made to use flip starts for the entire meeting."
The flip starts for the flat racing fixture use a stretching tape similar to that in jump racing and can mean a more uneven start for runners.
Appleby's trio of horses were among 18 horses from a total of 121 to be declared non-runners.
"I just don't think it's worth the risk. It would have made common sense to call the meeting off. It's not doing racing any favours whatsoever," added Appleby.
Fellow trainers Alan King and Graeme McPherson also withdrew their horses for similar reasons.
"We've pulled her [Homing Star] out because I am not at all convinced that we should be racing there," McPherson told BBC Radio Gloucestershire.
"We should be staying at home while businesses and people in Leicester are having to stay at home."
The city of Leicester has been placed back under lockdown measures after a spike in Covid-19 cases in the area.
Health Secretary Matt Hancock announced on Monday evening that all non-essential businesses would have to close again, with schools also closing from Thursday.
A BHA spokesman said: "Local authorities confirmed on Tuesday morning that, as racecourses are a place of work, and strict safety criteria are in place, today's [Tuesday's] fixture at Leicester racecourse has been given permission to go ahead.
"The fixture is being held behind closed doors. Only essential personnel are permitted to work at racing fixtures at present, and our guidelines require attendees to have little or no contact with the local community. Attendees are expected go straight to and from the venue.
"Every attendee undergoes a stringent three-stage medical screening process. Strict social distancing measures are in place.
"The health of participants and the public was uppermost in determining the procedures we have put in place for all race meetings."
Maykels told Racing TV that he believed it would be safe for another meeting at the course, on Tuesday, to go ahead although conceded the BHA may reschedule that fixture.