The Trans-Pacific Partnership, involving twelve Pacific-Rim nations, could be sealed in coming days, after talks that had drifted for five years narrowly escaped death in the US Congress.

"It could be done this week," said Trade Minister Andrew Robb last night, as he prepared to depart for what he hopes will be one final round of talks in Maui, Hawaii.

"There's no guarantees but the whole mood has shifted", he said, referring to a last-minute US Congress decision to give the White House autonomous negotiating powers.

"We're close enough, we're down to the really difficult ones – like sugar."

Aside from Australia's long-suffering sugar farmers, who have missed out in previous trade deals, Mr Robb said divisions remain over a US proposal to extend intellectual property protections for "biologics", which would increase the price of medicines.

Mr Robb said beef farmers were set to be winners alongside a range of professional services firms.

But the recent surge of negotiating momentum owes at least as much to geopolitics as it does to economics.

A range of nations that might once have bristled at American muscle-flexing are now encouraging it – as they hedge against China's growing propensity to throw its weight around.

Fairfax can reveal that the twelve prospective members have agreed to rules that would make it harder for the kind of state-owned enterprises which dominate China's outward investment profile.

"One rule is that governments can't give SOEs benefits that allow them to undercut the market," said one source close to negotiations, saying that SOEs would be penalised if they received discount loans when investing in TPP nations.

"Also, SOEs are not allowed to discriminate against other TPP parties in the way they sell and buy their products – it's an extension of government procurement rules," said the source.

Tellingly, it is understood that negotiations for this novel SOE chapter have been led by Australia, despite its reliance on Chinese trade, and endorsed by Vietnam, despite its own reliance on state-owned firms.

In another global first, the TPP will include enforceable anti-corruption provisions which will also have an outsized impact on Chinese firms.

They will mirror the OECD's anti-corruption guidelines and the UN Convention against corruptions, except that they will link to dispute resolution provisions.

And the single biggest winner out of this agreement is likely to be China's arch-rival, Japan.

The TPP will increase Japan's GDP by between 2 and 4 percent over a decade, according to estimates by economists at the International Monetary Fund.

Manuel Panagiotopoulos, from Australian and Japanese Economic Intelligence, said the TPP will provide Prime Minister Shinzo Abe with the impetus for much-needed domestic international reforms while laying a foundation for regional integration and security.

"What a lot of economists don't get is that geo-politics is more important than trade flows," he said.

"If the security foundation doesn't work then trade flows will dry up in an instant."

While China anxieties have loomed in the background of these negotiations, the economic giant could still join the group after the rules have been set.

"Both we and China should want to see China in the TPP – and sooner rather than later," said trade consultant Andrew Stoler​, formerly deputy director-general of the World Trade Organisation.

Earlier, when Mr Obama was wrestling with Congress, he told the Wall Street Journal: "If we don't write the rules, China will write the rules out in that region."

And US Defence Secretary Ashton Carter​ went further: "Passing TPP is as important to me as another aircraft carrier."

The twelve negotiating parties are Australia, Brunei, Canada, Chile, Japan, Malaysia, Mexico, New Zealand, Peru, Singapore, Vietnam and the United States.