Australia will ratify the Trans-Pacific Partnership after Labor resolved to support the 11-country trade agreement despite internal resistance over fears about its impact on Australian workers and scepticism about its economic value.

Overcoming hostility led by Left faction MPs and the union movement, Labor's trade spokesman Jason Clare announced new policies to tighten Australia's approach to future trade agreements.

Mr Clare's recommendation that Labor give the Morrison government the votes it needs to pass the enabling legislation was approved after a lengthy debate involving 23 speakers in Tuesday's caucus meeting. A slight majority of the speakers – including some Right faction MPs – opposed the legislation but the motion was ultimately passed without a formal vote.

A meeting of TPP-11 members in March. AP

Internal concerns centred on increased labour mobility for foreign workers, weak protections for Australians and whether the TPP-11 was consistent with Labor's policy platform. There is also resistance to allowing foreign multinationals to sue the government under investor-state dispute settlement provisions.

Backers of the agreement noted Australian exporters' improved access to global markets, defended its labour and environmental protections, and emphasised membership of the agreement would help Australia strengthen its role in the region at an uncertain strategic time.

Mr Clare said it was not protectionism to insist a company looked for Australian workers first before bringing in foreigners.

"Australia is a trading nation. Our economic growth is underpinned by our ability to sell our goods and services overseas," Mr Clare said in a statement.

"At the moment trade deals are negotiated in secret with not enough input from Parliament, industry, unions and civil society groups or the community. Labor will change that."

A Labor government would make labour-market testing compulsory, prevent Australia entering agreements that contain investor-state dispute settlement provisions, and introduce increased transparency and consultation in trade deal negotiations and a tougher national interest test.

Labor will attempt to negotiate side deals with members of the TPP-11 to strengthen labour-market testing and eliminate the investor-state dispute settlement provision for Canada.

The government needed the opposition's support after a majority of crossbench senators said they would oppose the legislation.

The TPP-11 – officially the Comprehensive and Progressive Agreement for Trans-Pacific Partnership – is the successor to the original TPP involving the United States. President Donald Trump withdrew the US from that partnership.

Greens trade spokeswoman Sarah Hanson-Young criticised Labor's decision, saying the TPP-11 would hurt Australian workers and make the government vulnerable to foreign corporations.

“Labor has betrayed Australian workers, and our sovereignty, by paving the way to locking our nation to the dangerous TPP,” Senator Hanson-Young said.

“It gives countries the ability to bring in temporary migrant workers with no need to first check if there are Australians ready, willing and able to do the job instead. This deal will result in Australia losing 39,000 jobs.

“It’s a bad deal, devised in a backroom and designed for a boardroom. It is baffling that Labor would support this deal.”