Australia's peak union body says federal Labor's demands over the China free trade deal do not go far enough and it will continue to campaign against the agreement.

The Opposition is demanding employers advertise jobs locally before hiring overseas workers, that the minimum wage be increased for people on 457 visas, and for more rigorous skills testing.

Opposition Leader Bill Shorten said the changes would be made in related legislation — not the deal itself — and the Government said it would consider the proposal in good faith.

But the Australian Council of Trade Unions (ACTU) said foreign workers would still enter Australia without market testing.

"There are still major gaps for us with the China free trade agreement (FTA) and we don't think these amendments to the migration bill will fix all of the problems," ACTU president Ged Kearney said.

"So the changes to the Migration Act do not cover all our concerns."

Unions have run television advertisements against the deal.

The ACTU is also holding more than 20 local forums across Australia and is challenging Coalition MPs to debate the agreement.

"I think until we're absolutely sure that our concerns are covered off we'll continue to campaign around this," Ms Kearney said after Labor's announcement on Tuesday.

"Given that there are still concerns, we will continue to have a conversation with our members and the Australian people about our concerns that remain."

MP argues Labor should be prepared to block China FTA

Victorian Labor MP Kelvin Thomson — who has questioned the benefit of many Australian FTAs — said Labor should not vote to ratify the China agreement if the Government does not agree to the party's demands.

"If the Government is not prepared to entertain these proposals, then I don't think the treaty should be ratified because I think the dangers for Australian workers are too great," Mr Thomson said.

"It's essential we have safeguards in place to make sure that there are provisions in this agreement that don't get abused."

But Australian Industry Group chief executive Innes Willox said business did not want the additional red tape being suggested.

"If the Government and the Opposition come to an agreement around labour market testing — that that not be any more onerous than the current labour market testing provisions already are — we don't find that labour market testing is necessary," Mr Willox said.

"It's costly [and] these are often in areas where business already knows there are labour shortages."

The Australian Chamber of Commerce and Industry said the Opposition's proposed changes were "shamefully opportunistic" and would have a major impact on businesses.