The Uniting Church has urged the Barnett government to consider legalising cannabis for medicinal use.

At its annual meeting at the weekend, the WA church's synod voted in favour of changes to state law so doctors could prescribe medicinal cannabis, which would be administered under supervision.

The push to legalise medical marijuana in WA is gaining momentum.

Medical cannabis has a high proportion of cannabidiol, which has a range of medical benefits and a low proportion of the intoxicating tetrahydrocannabinol.

Uniting Church WA acting general secretary Rosemary Hudson Miller said some attendees to the meeting shared personal experiences, describing how loved ones with chronic or terminal illnesses had found morphine inadequate for managing pain and suffered side effects such as nausea and vomiting.