A federal government frontbencher says he would be happy to see politicians drug tested in the same way as welfare recipients.

Key points: The idea was first proposed and then shelved in 2017

The idea was first proposed and then shelved in 2017 One positive test would result in being placed on income management and a referral to a rehabilitation program

One positive test would result in being placed on income management and a referral to a rehabilitation program The adding of heroin and cocaine to the list of drugs to test for is one of the changes

Under a plan being revived by the Coalition, people on Newstart and Youth Allowance who test positive for drugs including ice, marijuana, ecstasy, heroin and cocaine could be placed on income management or referred to rehabilitation programs.

The legislation was first proposed in 2017 but was shelved amid opposition from Labor and the Greens as well as medical and welfare groups.

The success of the new bill, being introduced next week, could depend on crossbench Senator Jacqui Lambie who previously called for the program to be expanded to include MPs.

"It should be random drug testing, so when I walk in here (Parliament House) and they say, 'You are going to lick the stick', then that's exactly what I'm going to be doing, and everyone else behind me on that random list," Senator Lambie said in 2017.

The government's leader in the Senate, Mathias Cormann, said he was not opposed to the idea.

"Personally I'm completely relaxed about that. I think if that is what it takes to get this very important reform through I personally would be entirely open to it.

"I'd be quite happy to advocate for that within the government," he told Sky News.

Prime Minister Scott Morrison also took to social media to add his support.

"BTW [by the way] I have no problem with drug tests for politicians. This is a requirement for many occupations these days," he said on Facebook.

"That should be considered for its own reasons, but this plan is about helping people get off welfare, off the dole and into work."

The two-year trial would see 5,000 welfare recipients tested for drugs at three trial sites - Logan in Queensland, Canterbury-Bankstown in New South Wales and Mandurah in Western Australia.

A welfare recipient who failed a drug test would be placed on income management with up to 80 per cent of their payments moved onto a cashless debit card.

A second positive test would result in a referral to a rehabilitation program, although earlier plans to also charge the recipient for the cost of the test, believed to be around $100, have been scrapped.

Social Services Minister Anne Ruston said the program would encourage people to get off drugs and into work.

"So what we're asking is please let us have the opportunity to trial it and once we've got that information and the data collected, then let's have an assessment as to whether the trial is worth rolling out more broadly," she said.

But shadow minister Linda Burney said it would cause further harm to vulnerable people.

"It is incredible that the government is just hell-bent on demonising people who are on welfare," she said.

"This has not worked overseas, it's expensive. And the way in which this needs to be treated, this issue of drug addiction, needs to be treated as a health issue."

Australian Council of Social Service policy director Jaqueline Phillips also attacked the decision.

"Community sentiment around people who are relying on welfare has really shifted in recent years, there's a lot more understanding about how difficult it is to make ends meet," she said.

"We fear what the government is trying to distract from the big issue which is galvanising community support around the country which is the need to leave to lift the Newstart allowance, the forty dollar a day payment, which hasn't been increased for 25 years."