Mr Chai said he had called on People’s Democratic Reform Committee (PDRC) leaders to stop protesting in Ratchaprasong as soon as possible, but is yet to receive a response.
He said business operators in the area normally generate 280 million baht a day in trade, but revenue has dropped by 60% since the PDRC began protesting at the intersection on Jan 13, since the number of Thai and foreign customers visiting the area has substantially dropped.
The number of commuters using BTS and MRT trains to travel to Ratchaprasong has fallen from 30,000 a day to 20,000.
Hotel occupation rates have also declined from between 85-90% to only 20%, while sales in food shops and restaurants have dropped 60%, Mr Chai said.
Business operators in Ratchaprasong are trying to protect the jobs of their existing 30,000-40,000 employees for as long as possible, he said, but warned they would have no other option but to make staff redundant if the protests are prolonged.
Protest leader Suthep Thaugsuban has declared that PDRC protesters will "completely shut down" Bangkok on election day on Sunday. Mr Chai said he is unable to estimate the possible damage to businesses since it depends on whether the rallies turn violent.