The Nick Xenophon Team has helped the federal government expand its cashless welfare card trial, backing down from the minor party's opposition to broadening the scheme.

The card will now be rolled out in Western Australia's Goldfields region after the government secured crossbench support in the Senate on Monday night, paving the way for the legislation's passage

The government shelved plans to take the trial to Bundaberg and Hervey Bay in Queensland, instead compromising on the single expansion site in WA.

The bill also secured a one-year extension to trial sites in Ceduna in South Australia and the East Kimberley region.

Labor opposed expanding the trial, saying there was insufficient evidence to justify expansion, while the Greens are against the card altogether.

"It looks like NXT are behaving like a sub-branch of the Liberal Party," Labor senator Doug Cameron told parliament.

But the government is confident there is enough evidence to show the card has been working to curb alcohol-fuelled violence and other social issues.

"The research found that the cashless debit card had been effective in reducing alcohol consumption and gambling, and it was also suggestive of a reduction in the use of illegal drugs," Liberal frontbencher Concetta Fierravanti-Wells said.

Under the trial, 80 per cent of a person's welfare payment is put onto a cashless debit card, which cannot be used to gamble or buy alcohol.

The remaining 20 per cent is put into a bank account and can be withdrawn as cash.