The Coalition Government first floated the idea of drug testing welfare recipients back in 2017, but the proposal floundered when Labor and the Greens opposed it. But guess what? It's back.

"The drug testing trial remains Government policy," new Social Services Minister, Anne Ruston, told Hack in a written statement, adding that the trial will only go ahead if it's passed by Parliament.

But the Government will be forced to look to the Senate crossbench (that is, politicians who aren't in Labor or the Coalition) to pass the bill, with both Labor and the Greens confirming they will continue to oppose the proposal.

The original idea was to test 5,000 people who are receiving Newstart or Youth Allowance in three trial sites: Mandurah in Western Australia, Logan on the outskirts of Brisbane and Bankstown in south-west Sydney.

The bill would allow testing of saliva, urine and hair follicles for drugs like cannabis, ice, ecstasy and heroin.

If the sample comes back as positive for those substances, the jobseeker would be put on welfare quarantining for two years. That means they would get their welfare money via a cashless debit card that would limit how they can spend it.

If the jobseeker has more than one positive drug test, then they would be forced to pay back the cost of the test and referred to rehab.

Hack asked the Government if any presence of an illicit drug would be enough for welfare quarantining to kick in, but we didn't get a response back from Minister Ruston's office. The Government has also refused to disclose how much the program will cost.

Does the bill have the numbers to pass?

The original bill was put on hold in late 2017 because the Government didn't have the support of the crossbench to pass it.

Labor and the Greens were opposed to the bill, meaning the Government needed the support of the other parties and independents in the Senate to get it through.

Healthcare bodies and aid groups nearly unanimously rejected the bill during a Senate inquiry, saying addiction should be treated as an illness, and questioning whether enough rehab facilities existed in the trial sites.

The Government flagged the possibility of bringing the bill back from the dead during the 2017 mini budget, called MYEFO, where it set aside extra cash for drug treatment facilities.

The Government has brought back the bill in the first part of its new term, after the election changed the make up of the Senate. It needs fewer crossbench votes - four, now - to get stuff passed through the Senate.

So Scott Morrison probably fancies his chances in this new Parliament.

Labor hasn't changed its mind on the policy.

"Experts are really worried because the evidence shows these kind of policies just don’t work – particularly when the services people need to deal with addiction aren’t available," Shadow Social Services Minister Linda Burney told Hack in a statement.

For this reason, Labor has opposed this counterproductive policy in the past, and nothing has changed.

The Greens still oppose it, too.

"It's extremely disappointing that the Government is seeking to reintroduce their bill to drug test people in our community on income support after it was rejected the community and health experts and couldn't get support in the last Parliament," Senator Rachel Siewert told Hack in a statement.

"The evidence at the several inquiries held into this bill heard that this punitive and cruel approach wouldn't work. Addiction is a health issue and must be treated as such."