The Federation of Thai Industries (FTI) is urging people to ignore calls to stop work and not pay their taxes as part of anti-government protests.
FTI chairman Payungsak Chartsuthipol said on Tuesday that the call for people to go on strike from Nov 13-15 as part of a civil disobedience campaign would damage the economy and erode confidence in Thailand in the international community.
He also opposed the call for people to withhold their taxes because the FTI supports the fight against corruption and tax evasion is a form of corruption.
The private sector believes the anti-government protests should be brought to an end, since the controversial amnesty bill has been rejected by the Senate and the coalition parties have confirmed they will not try to resurrect the legislation, he said.
The FTI has been unable to assess the economic damage caused by the protests so far, but if the rallies were to continue it would certainly have impact on the economy in the long-term, particularly the investment sector, he said.
Gross domestic product growth for 2013 may fall to only 3.5%, from the previous projection of 4%, said Mr Payungsak.
The 2014 economic growth forecast of 5% would also need to be reviewed if the protests were prolonged, he said.