Heavy-hitting progressive groups have sent a letter to Democratic presidential nominee Hillary Clinton, urging her to make "a clear, public, and unequivocal statement opposing any vote on the disastrous Trans-Pacific Partnership (TPP) in the post-election, 'lame-duck' session of Congress."

"Allowing a lame-duck vote would be a tacit admission that corporate interests matter more than the will of the people, relying on members of Congress who will be less accountable to voters."

The letter, also published at Medium, says Clinton's "continued leadership is sadly necessary as President [Barack] Obama refuses to abandon this unpopular deal."

Even as the White House gears up for an all-out, post-election push on the maligned 12-nation trade deal, "the American public and their elected representatives in both parties are increasingly coming to the conclusion that the TPP puts corporations ahead of human needs on jobs and wages, human rights, access to medicine, climate change and more," wrote the signatories, including environmental group 350 Action, the Communications Workers of America union, and grassroots political organization Democracy for America.

"In the face of such opposition," they continued, "allowing a lame-duck vote would be a tacit admission that corporate interests matter more than the will of the people, relying on members of Congress who will be less accountable to voters. Regardless of the outcome, a vote itself would send an unmistakable signal that the game is rigged in favor of elites and against everyday Americans."

To that end, the groups demand Clinton "immediately make a clear and strong public statement" against the vote.

The missive follows a concerted campaign calling on Clinton—who supported the TPP as secretary of state before coming out against it—to take the lead in killing the deal. In the past two weeks, more than 100,000 people have signed CREDO and Democracy for America petitions that make the same ask of Clinton. Nobel economist Joseph Stiglitz, who is advising Clinton on her campaign, also said Tuesday that to "rush [the TPP] through in a lame-duck session" would be "outrageous" and "wrong."

As for the candidate herself, she offered her "strongest words yet" against the TPP earlier this month—saying she would oppose the deal "after the election" and "as president"—but stopped short of pushing Obama on the issue.

Is that because, as Cenk Uygur of "The Young Turks" hypothesized this week, she knows that if she's elected, she'll have to support the deal?

Meanwhile, NBC News notes that Clinton's former primary rival, Sen. Bernie Sanders (I-Vt.), "used the launch of his new group Wednesday night to say he too was spoiling for a fight" on the corporate-friendly agreement, opposition to which was a cornerstone of his campaign.

"Let me be very clear. I will do everything that I can to defeat the TPP if it comes to the floor of the Senate, as I expect that it will," Sanders said during his Our Revolution live address. "The American people have got to stand together and say no to the TPP."