But the federal government could hit a fresh snag as its tries to convince the new-look Senate to support its twice-rejected proposal.

Tasmanian crossbencher Jacqui Lambie - whose vote will be crucial - is open to backing the reheated idea.

But only if federal politicians are also drug tested.

Lead government negotiator Mathias Cormann said he was "completely relaxed" about her demand.

"If that is what it takes to get this very important reform through, I personally would be entirely open to it and I'd be quite happy to advocate for that within the government," Senator Cormann told Sky News on Friday.

Labor frontbenchers are split over whether to support the resurrected plan.

Deputy opposition leader Richard Marles is open to the idea.

"We are for anything that will get people off drugs," he told the Nine Network.

"We will look at the legislation, but we want to know this works and we are mindful of the advice of experts around this.

"We have to be careful whatever measures we put in place don't demonise the most vulnerable."

However, Labor's social services spokeswoman Linda Burney is dead against it.

"We do not want to see the punitive measures of using people on Newstart and people on Youth Allowance as experiments in trying to treat a drug addiction," Ms Burney said in Sydney.

"This is ineffective, has proven to be ineffective in other countries, and is expensive. Frontline services is where the money should be spent."

The government wants to test Newstart and Youth Allowance recipients for illicit substances, quarantining payments for those who test positive, and replacing their obligation to find work with drug counselling sessions.

The two-year drug testing trial would be rolled out in three locations - Logan in Queensland, Canterbury-Bankstown in NSW and Mandurah in WA.

Social Services Minister Anne Ruston says people on welfare who take drugs are denying themselves the opportunity to get a job.

"We want to work with these people to get them job ready, to deal with their addiction so that they can get a job," she said.

"This measure is not about punishing people, it is about identifying people who need our help."

The Australian Council of Social Service has described the rehashed policy as "demeaning and flawed".

St Vincent's Health was suspicious the government would exhume the controversial idea.

"It's extremely disappointing but we thought this might happen," the not-for-profit organisation said.

"In fact, we wrote to Labor, the Greens and the Senate crossbench earlier this week asking them to remain firm in their opposition to this trial.

"We'll continue to stand against it."

A previous bill stalled twice in the Senate, before the coalition abandoned the idea.

Research has shown the unemployed are greater than three times more likely to use amphetamines, and one-and-a-half times more likely to use cannabis than the employed.

Australian Associated Press