The federal government will soon roll out taxpayer-funded advertisements spruiking the free-trade deal with China in a bid to combat a union scare campaign.

The ads, which also promotes free trade agreements with Korea and Japan, will cost $24.6 million.

About 200 road shows will be backed by television and print advertisements and a social media campaign.

The campaign is scheduled to start around October, possibly before parliament gives its tick of approval to the China deal.

Trade Minister Andrew Robb labelled the union campaign against the deal as "xenophobic, misplaced, misleading, lying".

"At the moment the union movement is playing a political game and they're trying to stop jobs being created in Australia for their own," he told reporters in Yass, near Canberra, on Wednesday.

Mr Robb challenged Labor to support the deal, saying it was a test for Opposition Leader Bill Shorten.

But Labor's trade spokeswoman Penny Wong says the government had questions to answer about safeguards for Australian jobs.

Independent senator Nick Xenophon said it was "grossly irresponsible" and "cowardly" to use taxpayers dollars to promote a deal which hadn't yet cleared parliament.

Crossbench colleague Glenn Lazarus is worried the government is giving away "very little" on the agreement's details.

"I think setting-up an ad campaign at this stage would be a total waste of money," he told ABC radio.