A southern Alberta meat packing plant where dozens of employees have tested positive for COVID-19 has now temporarily laid off 1,000 staff, according to the union representing them.

The Cargill plant in High River — about 60 kilometres south of Calgary — has roughly 2,000 workers.

United Food and Commercial Workers Canada Union local 401 president Thomas Hesse wrote to the company Sunday to request the plant close — given that there are 38 confirmed COVID-19 cases among the employees — and that employees be given time to self isolate.

Hesse said 1,000 staff were temporarily laid off Monday, and said staff who weren't included in the layoffs showed up for work Tuesday and were sent home.

He said after layoffs were announced, he received a response from the company to his letter — and the company accused him of being highly inflammatory, he said. UFCW is now considering legal action.

A company spokesperson confirmed the plant has temporarily reduced shifts by removing its second shift, effective Monday.

"This will allow us to minimize the impact of COVID-19 and continue to follow health department guidelines. This was a difficult decision for our team, but our values are guiding our actions," said John Nash, the North American lead for Cargill Protein.

We hear about conditions at a major meat packing plant in Southern Alberta during the COVID-19 pandemic. 7:06

Nash said the company has implemented temporary wage increases and bonuses, as well as safety measures like temperature testing, enhanced cleaning and sanitizing, prohibiting visitors, adopting social distancing practices where possible and offering staggered breaks and shift flexibility.

"Our facility will be back to operating at full capacity as soon as is it is safe to do so," he said.

CBC News asked for the company to confirm the number of employees impacted by the shift reduction, but has yet to receive a response. Cargill has also declined to confirm the number of confirmed cases among employees.

The Cargill meatpacking plant in High River, Alta., which is one of the main beef suppliers to McDonald's Canada, has 38 employees who have tested positive for COVID-19, according to the union representing workers. (McDonald's/The Associated Press)

Hesse said he remains concerned about conditions at the plant, as he said it's not a workplace built for physical distancing.

"In my entire life I have never experienced a situation that I'm told that just through a little proximity I could catch a disease," he said.

"And now you have them packed in there all together."

Alberta chief medical officer of health Dr. Deena Hinshaw said Tuesday she's aware of positive cases at the meatpacking plant, and said front-line medical officers in the Calgary zone are handling the situation.

She said any close contacts of those who tested positive are required to quarantine.

Alberta Agriculture Minister Devin Dreeshen said his department has worked with Alberta Health Services, the Canadian Food Inspection Agency, the unions and companies to ensure essential services like food-processing facilities can continue to operate through the coronavirus pandemic, and to ensure protocols are in place in the event of worker illness.

The plant processes thousands of cattle each day and is one of the two primary beef suppliers for McDonald's Canada.

According to the Canadian Food Inspection Agency, there are no reported cases of food or food packaging being associated with the transmission of COVID-19.

The total number of COVID-19 cases across Alberta rose to 1,870 on Tuesday.