Controversy over the State Department's upgrading of Malaysia in its annual human trafficking report continues to swirl, with one organization charging that it shows the administration watering down human rights abuses in an effort to "further its corporate trade agenda."

The latest Trafficking in Persons Report, released last month, has Malaysia downgraded from a Tier 3 ranking to a Tier 2 ranking. And, as the New York Times reported, that downgrade has impacts on the Trans Pacific Partnership (TPP) trade pact:

Congress recently granted President Obama fast-track powers to complete negotiations on the deal, but it included a caveat that prohibited him from doing so with countries listed in Tier 3 of the State Department report — that is, countries that are not making a significant effort to combat human trafficking.

[...] Its upgrade this year to what is known as the Tier 2 watch list, an intermediate step that indicates a country is trying to tackle human smuggling, immediately drew the anger of critics, who sought to link the improved standing of Malaysia to the trade deal.

Moving Malaysia to Tier 2, a Reuters investigation published this week found, came despite the opinion of human rights experts tasked with giving the State Department their assessments.

Now, House Democrats and senators from both parties are demanding answers about the decision—and the trade-related possible motives.

Reps. Keith Ellison (D-Minn.), Rosa DeLauro (D-Conn.) and Mark Pocan (D-Wis.) sent a letter (pdf) Thursday to President Obama and Secretary Kerry, writing that they are "concerned" about Malaysia's status change, as there is evidence that the country is not "making significant efforts to" tackle trafficking, as the upgrade would warrant.

Also on Thursday, the Senate Foreign Relations Committee held a hearing on the TIP report, where Senator Bob Corker (R-Tenn.), chairman of the committee, threatened to subpoena the internal communications that led to the status change.

"So the government convicted three traffickers for forced labor and one for passport retention, and our State Department, for that record, which is less than what they [Malaysia] did the year before,…raised their status,” Corker told Undersecretary of State Sarah Sewall. "I don’t see how anybody could believe there was integrity in this process."

Also speaking at the hearing was Sen. Bob Menendez (D-N.J.), who said that the State Department's "conclusions [on Malaysia's human rights] are not shared by any other concerned observers."

Jeff Conant, Senior International Forests Campaigner with Friends of the Earth, says the motivation is clear. He writes at Foreign Policy in Focus Thursday: "There’s only one reason why the State Department would change Malaysia’s status: to ease the country’s inclusion in the Trans Pacific Partnership, or TPP — a massive 12-country trade and investment pact currently being negotiated by the Obama administration.

"If President Obama is willing to overlook the brutal fate of Asian workers tossed into the sea, beaten lifeless, or worked to death on Malaysian palm oil plantations, how can we believe him when he says the TPP will have strong safeguards for people and the environment?" Conant writes.

Friends of the Earth was at a rally outside the Senate hearing Thursday to raise flags about the change its says may just be "downplaying modern-day slavery just to pass a trade deal."

Luísa Abbott Galvão, Climate and Energy Campaigner with the organization, said the move highlighted further problems with the pending trade deal.

"The sinister manipulation of what should have been an independently-conducted assessment of human rights efforts demonstrates the extremes to which President Obama is willing to go to further his corporate trade agenda," she stated Thursday.

"If President Obama is willing to deliberately downplay modern-day slavery to facilitate trade negotiations, we cannot believe his assurances that his trade deals will elevate environmental and social protections around the world," her statement continues. "This cynical episode further delegitimizes the TPP negotiating process, which has gone from undemocratic to outright dehumanizing."