Australia had led a group of nations objecting to the US position of allowing pharmaceutical companies keeping data for biologics, advanced medicines made from living organisms, secret for 12 years. Signatories to the TPP include Australia, Brunei, Canada, Chile, Japan, Malaysia, Mexico, New Zealand, Peru, Singapore and Vietnam. Since this 2015 photo the US has backed out. During that period, companies can block the manufacture generic versions of their drugs by competitors and set prices as high as the market will bear. Under the compromise data protection will now last only five years to eight years. Other points of contention overcome in this last round of negotiations included opening markets for dairy products and sugar and phasing out of tariffs on Japanese cars sold in North America.

Also in the final deal, tobacco companies were excluded from using tribunals set up to handle trade disputes in order to end the practice of them using trade agreements to sue nations that enacted anti-smoking laws. No deal: Protesters in Atlanta, Georgia, express opposition to the Trans-Pacific Partnership. This was applauded as a "a truly historic step for public health" by the US group Campaign for Tobacco-Free Kids. Australia's Minister for Trade and Investment, Andrew Robb, said in a statement that the deal would deliver "unprecedented new opportunities in the rapidly growing Asia Pacific region, with its rising middle class, for our businesses, farmers, manufacturers and service providers." Deserves credit ... Trade Minister Andrew Robb. Credit:Andrew Meares

In 2014, a third of Australian goods and services exports, worth $109 billion, went to TPP countries. Mr Robb said the deal would see Australia's market access for sugar double in the US, liberalises beef exports to Japan, and eliminates tariffs for beef into Mexico, Canada and Peru. Reaching agreement over the sprawling 30-chapter deal is seen as a major achievement for the Obama administration. In a statement US President Barack Obama said the TPP "includes the strongest commitments on labor and the environment of any trade agreement in history, and those commitments are enforceable, unlike in past agreements." It locks in one of the key legacy goals of the president before his second term ends and lends substance to the foreign policy "rebalance" to the Indo-Pacific region announced in Australia during his first term.

The US and other members aim to establish a rules-based approach to trade as China, which is not a member, continues its rise in the region. The US also sees strategic benefit in the TPP, believing that it will bind member nations closer together with the US, reducing the risk of conflict with China. What next? It is expected to be months before the final drafting of the document is completed and the US Congress will then have three months to review it before it votes or not to support it, possibly making the TPP active early next year. By then the US presidential primaries will be in full swing, and the deal is expected to be swept up in the ferocious political environment.

Most moderates from both parties support the deal in principal, while the left of the Democrats and parts of the Republican right have already voiced opposition. Hillary Clinton, a 2016 presidential candidate who as Secretary of State during Mr Obama's first term championed the rebalance, is now facing a challenge from Senator Bernie Sanders, who opposes the deal. A former supporter of free trade and the TPP, she now appears to be distancing herself from it, or maintaining a neutral stance at best. Mr Sanders has already vowed to do what he can to block it. "In the Senate, I will do all that I can to defeat this agreement," he said in a statement.

"We need trade policies that benefit American workers and consumers, not just the CEOs of large multinational corporations." Senior Republicans, including Paul Ryan, chairman of the powerful Ways and Means Committee of the House of Representatives, said they would review the deal before offering support. The senior Democrat on the Committee, Sandy Levin, welcomed the measures restricting the power of tobacco companies and advances in workers' rights standards in Vietnam and Malaysia, but said the deal appeared not to meet his expectations on similar standards for Mexico. Before the pharmaceutical IP compromise was struck, Senator Orrin Hatch of Utah, chairman of the Senate Finance Committee that has jurisdiction over trade, threatened to withdraw his support for the accord if United States negotiators agreed to such terms. He has now voiced his disappointment.

It is possible that Congress could strip the authority it has already granted for negotiating the deal from the president, and indefinitely delay it.