Proposed drug testing trials for welfare recipients will have their day in the Senate once again, despite continued opposition from those who sank the policy last time.

The controversial plan would allow 5000 new Youth Allowance and Newstart recipients across three locations in Queensland, NSW and Western Australia to be drug-tested.

It passed the lower house on Monday night, 73 votes to 67.

The trials were withdrawn from broader welfare reforms that passed parliament earlier this year after struggling to get Senate support.

Social Services Minister Dan Tehan reintroduced the legislation on its own in February.

Centre Alliance MP Rebekha Sharkie, whose party represents a crucial Senate voting bloc, indicated her party would again vote against the bill and questioned why the government was continuing to pursue it.

"We have so much to debate in this place so I cannot understand why we are expending more time on this when this particular part has already been resoundingly rejected by the parliament," she said.

Among their complaints is that the government has not said how much the trial will cost.

Ms Sharkie said she could only assume the legislation would have a "hefty financial cost" based on the cost of similar programs in the US, and her party would not support any legislation without knowing the cost.

Labor MPs also spoke against the policy, including Julian Hill who was booted from the chamber after unleashing a tirade on the policy's designers.

He repeatedly refused to withdraw remarks describing coalition MPs as "ignorant, prejudiced, scuzzbucket, brain-dead, moron bottom feeders" and left the chamber declaring he did so proudly.

His colleague Emma McBride earlier reflected on her experience with a harm-minimisation approach in her work as a mental health pharmacist at Wyong Hospital.

"If the government is genuine in its claim to help those burdened by dependence, a good first step would be properly funding units like this one and not attacking welfare recipients," she said.

Liberal MP Jason Falinski told parliament he'd welcome and encourage the policy being rolled out in his northern Sydney beaches electorate where locals "truly care about everyone in their community, our community, especially those trying to get back on their feet".

Anyone who tests positive for illicit drugs under the proposal would be forced onto cashless debit cards, which quarantine 80 per cent of welfare payments for housing and food expenses.

Multiple positive tests would result in referrals for treatment and refusing to take a test would see a person's welfare cut for four weeks.