Television host Andrew Denton is preparing to lobby Prime Minister Malcolm Turnbull to secure a lower house vote to pave the way for assisted dying to be legalised across Australia.

With a Senate vote on a private member's bill that would allow the ACT and Northern Territory to make their own euthanasia laws expected to go down to the wire on Wednesday night, Mr Turnbull has come under increasing pressure to stop the legislation reaching the lower house.

If the bill introduced by Liberal Democrat senator David Leyonhjelm passes in the Senate, Denton and his co-director of advocacy group Go Gentle Australia Brian Owler will write to Mr Turnbull demanding he allow it to be debated in the lower house.

Brian Owler Credit:Janie Barrett

Professor Owler, a former president of the Australian Medical Association, said it would be "disappointing" if Mr Turnbull succumbed to pressure from his conservative colleagues, given the widespread community support for euthanasia law reform.