Public Health Minister Anutin Charnvirakul has refused to back down from the move to decriminalise cannabis despite mounting calls for the policy to be immediately suspended.

Mr Anutin said on Tuesday that a House committee scrutinising the bill on cannabis and hemp is expected to finish work on the bill by the end of next month before presenting it for approval by parliament and royal endorsement.

Mr Anutin said Prime Minister Prayut Chan-o-cha has promised to push the bill through during the current parliamentary session.

"We cannot step back and make cannabis an illegal drug again. The plant is useful as a form of medical treatment and will benefit the economy. We have come too far [to turn back now]," said Mr Anutin, who also leads the Bhumjaithai Party.

He said regulations are in place to control the use of cannabis and that its abuse by children is also illegal.

Pushing through the decriminalisation of cannabis was among Bhumjaithai's flagship policies ahead of the 2019 election.

Over 850 doctors and staff at Ramathibodi Hospital are calling for the policy to be immediately suspended.

Addressing the doctors' concerns, a Bhumjaithai Party MP said the government is "doing its best to come up with more effective rules to seal off any remaining legal loopholes in our medical cannabis regulations".