Concerns have been raised over a "confusing" pilot plan proposed in the Greater Bay Area development blueprint to transfer hospital patients "across the border" for treatment.
A chapter named "Building a healthy bay area" in the blueprint released by Beijing on Monday briefly mentions that the authorities should study launching services to transfer non-emergency patients for "cross-border treatment" at designated public hospitals.
It doesn't specify whether the scheme should cater for mainland residents or Hong Kong people, or whether patients should be transferred from Hong Kong to the mainland, the other way around, or in both directions.
Speaking in Legco on Wednesday, Lam said the arrangement would be to cater for the needs of Hong Kong residents.
On an RTHK radio programme earlier in the day, the chairman of Hong Kong Patients' Voice, Alex Lam, said he was worried that if proposal is adopted, such transfers would further burden public health services in the SAR.
He said Hong Kong residents in mainland hospitals can already be taken to a border point and transferred by a Hong Kong ambulance to hospitals in the territory.
Alex Lam said what is being proposed in the blueprint is confusing, and he urged the Hong Kong government to clarify it.
"We're already seeing the overloading situation for quite a long time. If the government is not doing something to improve this, we have to say no to the scheme," he said.
The President of the Medical Association, Ho Chung-ping, warned that impact would be "severe" if mainland patients are taken to public hospitals in Hong Kong.
But he pointed out that currently, most mainlanders who seek medical treatment in Hong Kong go to private hospitals.
The Food and Health Bureau said on Tuesday that the government supports the idea of designated hospitals on the mainland transferring Hong Kong patients back to the SAR using ordinary vehicles.