Don't let trade deal slip: China envoy

China's ambassador has delivered a muted warning to Australia about a free-trade deal the two nations took 10 years to negotiate but yet to be approved by parliament.

"This is an opportunity that should not be allowed to slip through our fingers, should not be allowed to slip away," Ma Zhaouxu said in a speech overnight in Melbourne to mark the 100th day of the official signing of the agreement.

Labor and trade unions are demanding the government legislate supplementary conditions to the agreement that protect local jobs and wages and conditions.

Foreign Minister Julie Bishop called on Opposition Leader Bill Shorten to support the agreement in Australia's national interest.

"I'm deeply concerned that Labor is beholden to the CFMEU and other unions who oppose a job-creating strategy and a free-trade agreement," she told reporters in New York.

Acting opposition leader Tanya Plibersek insists Labor supports the agreement.

But it wants assurances there will be labour market testing so jobs would be offered to Australians first.

"We want assurances that the skills level and the pay of people who are coming in from China to do work won't undercut the skills or pay of Australian workers," Ms Plibersek told reporters in Sydney.