More than 10 countries are in talks with Beijing to sign bilateral tax agreements that would exempt their nationals and companies from paying the new social security tax.
Hong Kong, with hundreds of thousands of residents working on the mainland, will be most affected, with both workers and firms sharing the burden. But the government has only been 'reflecting Hong Kong businesses' concerns to the mainland authorities through established communication channels', according to a government spokesman.
The United States, Japan and Russia are among countries negotiating with Beijing.
The final draft of the national Social Insurance Law - originally scheduled to be implemented on July 1 - has now been finalised. It is waiting for State Council approval, according to a person close to the situation.
All foreign workers will have to contribute to social security insurance, which covers medical insurance, unemployment benefits, work-place injury protection, maternity leave and a housing provident fund.
Under the plans, a foreign worker earning 10,000 yuan (HK$12,068) a month would pay 1,800 yuan in social security, plus 335 yuan in income tax - more than 21 per cent of their salary.