The Joint Standing Committee on Commerce, Industry and Banking (JSCCIB) predicts that 7 million workers will be out of a job by June because of shutdowns from the pandemic.
The committee said most of the layoffs will affect low-paid workers, with 6 million out of the 7 million workers losing their jobs earning less than 20,000 baht a month, said Supant Mongkolsuthree, chairman of the JSCCIB and the Federation of Thai Industries.
An estimated 4.2 million retail and shopping mall workers will lose their jobs, along with 1 million construction workers, 978,000 hotel workers, 250,000 restaurant workers, 200,000 spa and massage workers and 200,000 garment factory workers.
The JSCCIB is still assessing the outbreak's impact on employment in the automotive and electronics sectors, as well as at department stores.
Thailand's labour market employs about 38 million workers.
"Even though the outbreak is expected to end within the first half of 2020, the economy will take time to recover," Mr Supant said.
The JSCCIB is maintaining its macroeconomic forecast, deciding to wait and see about the effects of the government's 1.9-trillion-baht stimulus package.
The panel forecasts an export decline of 2% and inflation of 0.8-1.2% while maintaining a 2-2.5% GDP growth forecast, despite the more ominous projection of -5.3% by the Bank of Thailand.
"The committee wants to thank the government for approving the 1.9-trillion-baht economic stimulus package," Mr Supant said. "The JSCCIB expects the economy to enter a recession, with estimations that the outbreak will cost the economy more than a trillion baht."
The group is expected to downgrade projections from February to a 5.3% GDP contraction and an 8.5-10% drop in exports this year.
Kalin Sarasin, chairman of the Thai Chamber of Commerce, is calling on the government to support employees taking leave without pay to quarantine.
"These people should get government relief measures in the form of 50% of their monthly salaries," he said. "The JSCCIB proposes hourly wages for employees at 40-41 baht per hour for four hours, but not for over eight hours per day, in line with the minimum daily wage of 325 baht per day."
The government must help companies considering laying offs keep their workers through provisions of the Social Security Act, with the government paying 50% of wages and companies paying 25% for workers earning below 15,000 baht a month, Mr Kalin said.