Thailand will announce visa-free access for holders of the SAR passport today, reversing an earlier decision.
The turnaround follows intensive lobbying by Hong Kong, British and Chinese officials. Thailand is the most popular destination for Hong Kong people after China.
Foreign Minister Prachuab Chaiyasan was likely to make the announcement during a visit to the territory, sources said.
Thai diplomats visited Hong Kong this month to inspect the blue-covered SAR passport and met immigration and Security Branch officials.
The Thai Cabinet rejected appeals for visa-free access in November, partly because of uncertainty about stability after the handover. But it later agreed to review the decision, with a view to protecting its rapidly growing and lucrative tourism market.
The Philippines dropped its visa requirement in March, also after strenuous lobbying.