Legislators voted 177 in favour and two against to ban surrogacy except in cases involving a relative, with violators facing up to 10 years in jail.

Eighteen MPs have been appointed to review the legislation after it passed a first reading, signalling the determination of Thailand's military rulers to shut down a booming surrogacy industry.

The revelation in August that Gammy, who has Down syndrome, was abandoned by his Australian parents David and Wendy Farnell prompted raids that targeted dozens of fertility clinics across Bangkok.

The Farnells took Gammy's healthy sister Pipah to their home in Bunbury, Western Australia, leaving Gammy, who at that time was critically unwell.

MP Kitti Waseenout told parliament that unethical and illegal surrogacies "have gone on for too long."

Thailand's conservative Buddhist society was shocked by the Gammy case and others that have emerged since August.

A 24 year-old Japanese businessman fathered at least 15 babies through surrogate Thai mothers, telling police he wanted to have more than 20 babies to take care of his many businesses.

Meanwhile, Australian authorities are expected within days to approve Australian citizenship for 10-month-old Gammy who will be eligible for medical and other benefits in Australia.

The boy's mother Pattharamon Chanbua applied for his citizenship on the basis that Mr Farnell is his biological father.

Ms Pattharamon has said previously that Mr Farnell provided sperm and an unnamed Thai woman provided eggs that led to her carrying Gammy and Pipah under a commercial contract for Mr Farnell and his wife Wendy.

She says citizenship will be an additional safeguard for Gammy who is being provided medical and other care by the Australian Charity Hands Across the Water.