President Obama this week stepped up pressure on his fellow Democrats to approve fast-track trade authority that would ease passage of the Trans-Pacific Partnership, at times strongly criticizing what he deemed “dishonest” claims—and Saturday, two leading Senate liberals responded.

Senators Elizabeth Warren and Sherrod Brown sent Obama a letter demanding that he release the bracketed negotiating text of TPP before Congress votes on fast-track authority. The duo noted that even George W. Bush released the texts of the Free Trade Agreement of the Americas “several months” before congressional action was required, and asked Obama to do the same.

In comments to reporters Friday, Obama said “The one that gets on my nerves the most is the notion that this is a ‘secret’ deal.” In a shot widely interpreted as directed at Warren, he said: “Every single one of the critics who I hear saying, ‘this is a secret deal,’ or send out emails to their fundraising base saying they’re working to prevent this secret deal, can walk over today and read the text of the agreement. There’s nothing secret about it.”

Warren and Brown took this claim on directly in their letter:

In recent remarks, you suggested that critics of the TPP are “dishonest” when we claim that TPP is a “secret deal.” Even though negotiations over TPP are largely complete, your Administration has deemed the draft text of the agreement classified and kept it hidden from public view, thereby making it a secret deal.

As a result of your administration’s decision, it is currently illegal for the press, experts, advocates, or the general public to review the text of this agreement. And while you noted that members of Congress may “walk over…and read the text of the agreement”—as we have done—you neglected to mention that we are prohibited by law from discussing the specifics of that text in public.

While experts, the public, and the press are not allowed to review the latest draft of the TPP, executives of the country’s biggest corporations and their lobbyists already have had significant opportunities not only to read it, but to shape its terms. The Administration’s 28 trade advisory committees on different aspects of the TPP have a combined 566 members, and 480 of those members, or 85%, are senior corporate executives or industry lobbyists. Many of the advisory committees—including those on chemicals and pharmaceuticals, textiles and clothing, and services and finance—are made up entirely of industry representatives.

They went on to call for the bracketed negotiating texts to be released before fast-track approval is granted. “The American people should be allowed to weigh in on the facts of the TPP before Members of Congress are asked to voluntarily reduce our ability to amend, shape, or block any trade deal,” they wrote.

Warren and Brown also noted that the fast-track bill being considered in Congress now could be in effect until 2021, meaning future presidents (i.e., President Scott Walker) could use the authority it grants to ram through even worse trade deals with no amendments possible, and a low vote threshold.

The fast-track legislation has passed both the House Ways & Means Committee and the Senate Finance Committee, and awaits full floor action in the coming days.

Warren and Brown’s letter can be seen in full here:

Elizabeth Warren and Sherrod Brown’s letter to Obama on trade