Foreign Minister Julie Bishop has urged business to get into the trenches and join the government against a militant union campaign opposing the free-trade deal with China.

Business had a duty speak up about the “boundless” employment, services and investment opportunities that would stem from the agreement.

“There’s a disgraceful campaign going on at present, backed by the unions,” Ms Bishop told a business leaders summit in Canberra.

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She said it sent an “appalling message diplomatically”, and had the potential to cause tension to Australia’s relationship with its largest trading partner.

“Derr, it’s a no-brainer,” Ms Bishop said, as she called on business to help counter the “outright lies”.

“The government will do its part but we also hope those who support free-trade agreements will be part of our efforts to point out the obvious benefits,” she said.

Earlier, Treasurer Joe Hockey warned the union campaign risked Australian jobs.

“They’re not willing to look past short-term point scoring to see the tremendous opportunities this agreement brings to all businesses small or large,” he said.

Rather than accept the world was changing the unions wanted to live in the past and fight for fringe interests, he said.

In parliament, Immigration Minister Peter Dutton accused union bosses of involving themselves in a racist attack.

They were also running a xenophobic campaign over the skilled workers 457 visa program.

“But as it turns out trade unions have sponsored 45 457 visa holders over the past five years with several unions still acting as a sponsor today,” Mr Dutton said.

– AAP