"This is all about U.S. politics and trying to prevent Congress from knocking Malaysia out of the deal, and this constitutes a blatant perversion of the integrity of the TIP report process," he said.
"If one looks at Malaysia's anti-trafficking record over the past year, victims are still being treated shoddily, migrants are still vulnerable and regularly mistreated, Rohingya graves are still being found, and arrests and prosecutions are still sporadic - so where's the improvements?" Robertson added.
Citing U.S. officials, the Reuters news agency on Wednesday reported that the State Department was to upgrade Malaysia from the bottommost Tier 3 category to the Tier 2 Watch List in its annual Trafficking in Persons Report (TIP), which is due out soon.
The TIP evaluates how each country performs in a given year in combating people smuggling trafficking on its territory, covering the period from April 1 to March 31 of the following year.
The upgrade would allow the U.S. to trade under the deal with Malaysia, a signatory to the TPP, according to Reuters. In June, Congress passed a related bill that prevented countries on the Tier 3 list to be part of such multilateral trade agreements.
Last month, the director of the U.S.-based Alliance to End Slavery and Trafficking (ATEST) told BenarNews that the trade legislation push could impact TIP report rankings.
"This year, Congress is debating whether to impose anti-trafficking considerations for countries seeking trade benefits with the United States," Melysa Sperber said in an interview.
"We are concerned that this policy shift may pressure the State Department to upgrade Malaysia to Tier 2 in order to preserve U.S. trading relations with this important partner."
'Still being finalized'
On Thursday, State Department officials declined to confirm reports about the imminent upgrade for Malaysia.
"The Trafficking in Persons report is still being finalized. It would be premature to speculate on any particular outcome," State Department Spokesman John Kirby said in a statement sent to BenarNews.
"Whatever conclusions are reached with respect to individual countries will be both based on a pragmatic analysis of the best information possible and reinforce our strong interest in human rights around the world."
In Malaysia, Glorene Das, director of Tenaganita, a Kuala Lumpur-based group that advocates rights for migrant workers, reacted angrily to news of the country's possible upgrade.
"If this is for real, damn you, U.S. Government! How are you any different than the corrupted government of Malaysia?" Das said Thursday in a statement posted on Tenaganita's Facebook page.
"It ought to concern every person, because it is a debasement of our common humanity," she said, adding that human trafficking "must be called by its true name – modern slavery."
"If we are upgraded," Das went on to say, "then it is very clear that trade is more important to [the] U.S. than the issue of human slavery!"
As many as two million undocumented migrants work in Malaysia and many are widely believed to be trafficked into the country via southern Thailand. This past May and June – on both sides of the Thai-Malaysia border – the bodies of scores of trafficking victims were uncovered at abandoned people-smuggling camps in the jungle.
Charles Santiago, a Malaysian lawmaker and member of the opposition Democratic Action Party (DAP), echoed the criticism voiced by human rights groups.
"It is totally disappointing to move Malaysia up to Tier 2 [Watch List] to enable participation in the TransPacific Partnership trade deal [TPPA]. We can then conclude that U.S. President Barack Obama is not serious about the TIP report," Santiago told BenarNews by phone.
"Malaysia did not deserve to be moved up from the lowest rank of the report. In less than 12 months, the U.S. is singing a different tune," said Santiago, chairman of the ASEAN Parliamentarians for Human Rights.
"And I am left wondering as to why. Pushing Malaysia to Tier 2 is violation of human rights," he added.
Attempts to reach Malaysian Home Minister Ahmad Zahid Hamidi for reaction to the reports were not successful. His staff said he was on vacation and out of the country.
By Nani Yusof and Uayporn Satitpanyapan