Labor is accusing the government of "demonizing" poor people by making a third attempt in three years to pass legislation that would take away welfare payments to those who test positive for illegal drugs.

"Randomised drug testing could see a 55-year-old being expected to urinate into a cup somewhere to prove that they are not a drug addict," said Opposition social services spokesperson Linda Burney, the Labor MP for Barton, NSW.  "That is inappropriate." 

The Morrison government wants to subject about 5000 new recipients of Newstart Allowance and Youth Allowance to testing for a range of illegal drugs, including ice, ecstasy, marijuana, heroin, and cocaine.  The two year program would be rolled out in three places: Logan, Queensland; Canterbury-Bankstown, New South Wales; and Mandurah, Western Australia.

Labor and The Greens managed to stall a previous version of the scheme in the Senate after welfare and medical groups objected on grounds of fairness.

Social Services Minister and Senator Anne Ruston counters that the plan would "identify and encourage people with substance abuse issues to get treatment, rehabilitate and make them job-ready".

Ms. Burney doesn't buy that.

"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."

And just like the last times the Liberal Party has brought it up, social service professionals are objecting.

"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," said Australian Council of Social Service (ACOSS) policy director Jaqueline Phillips.  "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."

"Not only is this proposal demeaning, there’s no evidence that it would work," Ms. Phillips said.