The Federal Opposition says it still has concerns about the China-Australia Free Trade Agreement (ChAFTA), as the Chinese ambassador warns against letting the deal "slip away".

China's ambassador to Australia Ma Zhaoxu used a speech in Melbourne to promote the benefits of the ChAFTA, as the stand-off continues between Labor and the Federal Government.

The Federal Opposition and the trade union movement renewed calls to include greater labour force protection as part of the enabling legislation.

The move is being resisted by the Federal Government.

Ambassador Ma told a business function in Melbourne the agreement was a "baby" that needed to be nurtured.

"ChAFTA took both countries 10 years of negotiations. It represents a hard win," he said.

"And this is an opportunity that should not be allowed to slip through our fingers, should not be allowed to slip away."

Ambassador Ma delivered the speech to mark the 100th day of the official signing of the agreement, which the Federal Government said would deliver a major windfall for the Australian economy.

"In the Chinese tradition, a celebration event should be held for the 100th day of a newborn baby. ChAFTA is just like a newborn baby of the two countries," he said.

"The sooner ChAFTA comes into force, the quicker it will benefit producers and consumers in both countries."

Acting Opposition Leader Penny Wong said Labor still held concerns about the bilateral agreement but was keen to find an agreement with new Prime Minister Malcolm Turnbull over labour force restrictions.

"We have made clear to him we want to find a way through here," Senator Wong said in a press conference held before Tuesday night's speech by Ambassador Ma.

"But we need to see safeguards, supplementary safeguards to the agreement around jobs, around Australian wages and conditions, avoiding the exploitation of migrant workers and of course maintaining Australian standards when it comes to our trades.

"Now, we are willing to sit down with him and find a way through this. The failure of the Government to do that, I think, speaks volumes."

Delaying could cost Australia 'key strategic advantage'

Opposition Leader Bill Shorten has spoken to Mr Turnbull over the phone on the issue, but the pair are yet to hold official face-to-face discussions.

Minister for International Development Steve Ciobo told the conference any delay in ratifying the agreement could see Australia lose a key strategic advantage.

"China is yet to ratify a free trade agreement with any other G20 country and as a nation we must seize this day and we must do so without delay," he said.

He urged those in the Federal Opposition, who want the agreement, be given the green light to speak up.

"I know there are plenty of people in the Australian Labor Party who are neither anti-trade nor anti-China," he said.

"I want each of them to come together to send a clear and consistent message to Bill Shorten to move away from the extreme fringe and to join the Coalition in supporting this China-Australia Free Trade Agreement."