Toomey's consternation came in tandem with rising GOP annoyance with the administration for negotiating a trade deal that they say is too liberal. The White House dispatched U.S. Trade Representative Robert Lighthizer to meet Thursday morning with Senate Republicans on the Finance Committee and to speak to the caucus at its lunch, amid fears that Republicans may rebel against one of President Donald Trump’s signature accomplishments.

In the Finance Committee meeting, Sen. John Cornyn (R-Texas) told Lighthizer that the Finance Committee couldn’t review the trade deal due to the way the administration negotiated it with Speaker Nancy Pelosi. Cornyn said he’s likely to support the agreement but expressed concern his committee had been “frozen out.”

“It leaves a little bit of a bitter taste in people’s mouth,” he said after the meeting. “I just don’t like being jammed."

Pelosi and the White House announced earlier this week that they had reached an agreement on the landmark trade deal after months of negotiation. But some Republicans are worried about its provisions, particularly after an endorsement from AFL-CIO President Richard Trumka.

Toomey (R-Pa.) described the deal as a "terrible new standard” for future trade agreements.

A spokesperson for Toomey said the senator “stands by the critiques he has” of the deal but doesn’t comment on private conversations.

Eric Ueland, White House legislative affairs director, acknowledged “there are people with strongly held points of view.”

“We respect that, we’re not being in any way argumentative, we’re simply here to be informative and advocate,” Ueland said.

At lunch, Lighthizer told Senate Republicans that the new agreement "is still a big improvement over NAFTA but not quite as good as the deal he had originally negotiated," according to Sen. Roy Blunt (R-Mo.). Blunt said senators asked questions primarily about changes in the final deal, including on removing special protections for prescription drugs and labor inspections.

Toomey raised substantive concerns with the deal, including a key provision over prescription drugs, in two meetings with Lighthizer on Thursday and in a phone call earlier this week. He also said he doesn’t understand how the agreement can retain its protections from a filibuster without waiting the 30 days required by the Trade Promotion Authority law.

“I don’t think we’ve had such a clear violation of TPA procedures in a trade agreement that attempts to invoke TPA,” Toomey told reporters after the lunch with Lighthizer. “It’s hard for me to imagine that you can retain the [51-vote] vote privilege that the TPA bestows on a piece of legislation if you’re not following TPA.”

Despite the griping from Republicans at the lunch, however, it didn’t appear that many Republicans were eager to join Toomey in opposition.

"It’s imperfect, and some people are concerned about the more recent negotiations,” said Sen. Kevin Cramer (R-N.D.). “The vast majority of us feel he got the best deal he could get. It’s still better than NAFTA.”

“It’s going to do well in there. There’s some opposition to some pieces of it, as you might imagine, but overall it’s a big jobs bill,” said Sen. David Perdue (R-Ga.), who said he did not expect mass defections.

Republican senators earlier this week expressed skepticism about the final product. Even Senate Majority Leader Mitch McConnell (R-Ky.) appeared dissatisfied. When asked Tuesday at a news conference about the deal’s substance, the GOP leader said "it's not as good as I had hoped.”

Still, most Republicans are likely to back the deal and GOP supporters are confident it will be approved. Sen. Chuck Grassley (R-Iowa) said that compromise was necessary to get the deal through.

"We got a Democrat House, and a Republican Senate and two countries to negotiate with and under those circumstances you have compromise," he said.

The House is expected to pass the trade deal before it leaves for the holiday recess, and the Senate will take it up next year after the impeachment trial of President Donald Trump.

Because the deal is likely to be considered under fast-track trade rules, it can pass with a simple majority.

