The Trans-Pacific Partnership (TPP) got a chilly reception in Washington on Monday from members of the US Congress, indicating it may have a tough slog ahead.

US President Barack Obama, who made the TPP one of the pillars of his foreign policy agenda as part of a focus on Asia, must now push the measure through Congress. It would liberalize trade in a wide swath of countries from Chile to Japan, covering about 40 percent of the global economy.

"While the details are still emerging, unfortunately I am afraid this deal appears to fall woefully short," Senator Orrin Hatch, a key Republican voice on international trade, said Monday.

Even Democrats - alarmed that the deal will erode environmental regulations and export more US jobs overseas - have also urged caution.

House Democrat Louise Slaughter vowed to work with her counterparts in Canada and Australia to derail the deal, which she said would allow the import of unsafe foods and restrict access to affordable medicine.

The deal had been negotiated largely in secret with few details known until now. But critics, working from leaked documents, have long warned that the deal would erode national sovereignty.

That's because it would enable multinational companies to challenge different countries' laws and regulations in private tribunals on the grounds they inhibit trade, undermining local laws on public health and the environment.

TPP criticized by labor, health advocates

But in a statement Monday, the trade ministers meeting in Atlanta insisted that the TPP has safeguards that prevent "abusive and frivolous claims and ensure the right of governments to regulate in the public interest, including on health, safety and environmental protection."

Whether these safeguards would be sufficient to allay fears is one of the crucial tests that lawmakers in Washington and the other 11 signatories will need to weigh carefully.

US presidential candidate Bernie Sanders, an independent running for the Democratic nomination, has vowed to do what he can to organize opposition inside the US Senate.

"This agreement follows failed trade deals with Mexico, China and other low-wage countries that have cost millions of jobs and shuttered tens of thousands of factories across the United States," Sanders said.

But for all the complexities of the trade deal it's a take-it-or-leave-it proposition. That's because the US Senate passed legislation last June granting Obama so-called "fast-track authority" meaning lawmakers can only vote yes or no, not offer their own amendments.

Obama has pitched the TPP as a way to open new markets for US companies in the Pacific Rim and compete with China.

"When more than 95 percent of our potential customers live outside our borders, we can't let countries like China write the rules of the global economy," he said. "We should write those rules, opening new markets to American products while setting high standards for protecting workers and preserving our environment."

Unions and other labor groups - traditional supporters of Obama's Democratic Party - remain unconvinced and have publicly criticized the president's handling of the negotiations.

"Rushing through a bad deal will not bring economic stability to working families nor will it bring confidence that our priorities count as much as those of global corporations," said AFL-CIO President Richard Trumka.

Obama can expect help from more business-friendly Democrats and many Republicans. Even as GOP leaders publicly express skepticism, some have already hinted that they will support it.

Republican Representative Kevin Brady, a senior member of a key committee overseeing taxes and tariffs, said in a statement: "Done right, this agreement will open a billion middle class customers to American goods and services."

When lawmakers will be tasked with considering TPP isn't clear but the PR push has already begun.

White House spokesman Josh Earnest said he could not provide details of the timeline for moving forward as details of the agreement still needed to be finalized and translated.

Disagreements over rules for the automotive, dairy and pharmaceutical industries had proved late sticking points as negotiations for the deal entered their final hours over the weekend.

The US and European Union are currently negotiating a separate trade deal - the Transatlantic Trade and Investment Partnership - which would create the world's largest free trade zone.

Like the TPP, negotiations are conducted behind closed doors and its proceedings have largely been kept out of the public eye.

The Obama administration faces a time crunch to finalize both trade deals before the president leaves office in 2017. The November 2016 presidential and congressional elections will also be a factor and may stall talks on the European deal.

jar/cmk (Reuters, AFP, dpa, AP)