Business groups felt the amendments would increase red tape but he Business Council of Australia said it could live with the changes if that meant getting he deal through.

Trade Minister Andrew Robb said he and Immigration Minister Peter Dutton would scrutinise the proposals but, prima facie, they met the government's criteria that there could be nothing that would change the substance of the agreement, nor single out China.

"At first glance, the things they are asking for are either providing clarity or they provide greater confidence to existing measures," he said.

As forecast by Monday's The Australian Financial Review, the government is likely to accept the amendments to ensure the deal comes into force before the end of the year and the benefits flow immediately.

Opposition Leader Bill Shorten with trade spokesman Senator Penny Wong. Andrew Meares

Opposition trade spokesman Penny Wong prevailed in securing caucus support on Tuesday morning to make three non-discriminatory changes to the Migration Act that would not affect the terms of the agreement nor specifically mention China.

The first change would mandate local labour market testing before low-skilled Chinese workers could be brought in on 457 visas for projects worth $150 million or more. The government has already said it would insist on this.

The second requests the base rate of pay for 457 visa workers, which the Abbott government froze, be increased from about $54,000 a year to $57,000 and indexed thereafter.


Skill certification required

The third requires that skilled workers brought in under 457 visas have their skills certified as a condition of obtaining a visa.

The FTA allows skilled workers such as nurses, engineers, electricians, plumbers, welders and carpenters.to be brought in without labour market testing.

Senator Wong explained that for Labor to insist on this being changed would be to change the text of the agreement, which Labor has said it cannot do. The government says the Chinese will walk away from the deal if the actual substance is changed.

"Obviously, had we been in government, we would have a different agreement but this is the agreement the Parliament's been presented with so what we are doing there instead is seeking to lift the wages … because that is one important step of dealing with the potential issue of exploitation," Senator Wong said.

For the same reason, Labor abandoned an initial demand that the FTA be stripped of the Investor-State Dispute Settlement mechanism, which would enable a Chinese company legal recourse against a policy decision by an Australian or state government should it feel it contravened the agreement.

The dumping of this and labour market testing for skilled workers was the main cause of dissent in caucus.

The safeguards are not retrospective.