Treasury Secretary Steven Mnuchin is making the case to Senate Republicans that they should stop an effort to block sanctions relief against three Russian companies.

But as he left Tuesday’s Senate Republican lunch, Mnuchin did not seem certain about the vote count ahead of an expected Tuesday afternoon vote on a motion to proceed to a resolution disapproving of the sanctions relief proposed for En+ Group plc, UC Rusal plc and JSC EuroSibEnergo.

The three companies had been sanctioned because they were under the control of Oleg Deripaska, a sanctioned Russian oligarch.

“This shouldn’t be a political issue. This is an issue of great importance. We have been tougher on Russia with more sanctions than any other administration. We sanctioned Deripaska. He will continue to be sanctioned,” Mnuchin said. “We have rules and regulations that we applied.”

“This was a long negotiation that was led by longtime career people,” he said of the eventual agreement with the three companies to have Deripaska’s ownership stake reduced.

Mnuchin said that the rules of the current sanctions law were being correctly applied, and several senators in the room said that some Republicans thought the better approach would be to review the underlying sanctions law rather than move ahead on the disapproval resolution introduced by Senate Minority Leader Charles E. Schumer, D-N.Y., under expedited procedures.

That group includes Sen. Mitt Romney.

“Whether the company has followed the law as it was written by Congress or not. That’s the key, because there are things you’d like to do and things you don’t want to do,” the Republican from Utah said. “But the key is we’re a nation of laws, you’ve got to follow the law. I want to read exactly what the law said with regards to applying sanctions and whether the company has followed that law and falls within it, or has not. If it’s followed the law then we have no choice but to execute the law as it was written. And perhaps if we don’t like the way the law is written, go back and see if we can’t improve it in some way.”

Sen. Susan Collins, a Maine Republican, said she would not decide on how to proceed with the disapproval measure until reviewing additional material in the closed meeting room of the Senate Intelligence Committee.

“I think it was very helpful for them to hear directly from me. I also brought up our senior team,” Mnuchin said. “Our view is that we have great responsibility in managing the sanctions programs all over the world, and we take those responsibilities very seriously at Treasury.”

Mnuchin said that the companies approached the Treasury about getting delisted.

In a Tuesday floor speech, Schumer was encouraging Republicans to cross the aisle and vote for the disapproval resolution.

“Beyond the weak terms of the deal, the Senate must consider that Deripaska has deep ties to President Putin and his intelligence apparatus, organized crime, and Mr. Paul Manafort, a subject of the Special Counsel’s investigation. It is deeply suspect that the Trump Administration would propose sanctions relief for Deripaska’s companies before the Special Counsel finished his work,” Schumer said. “We should not allow any sanctions relief for President Putin’s trusted agents or the companies they control before the conclusion of the investigation.”

Mnuchin did not say whether he thought he or Schumer would win out on the policy issue.

“That’s up for the Republicans to decide,” Mnuchin said.

There were questions on both sides of the Capitol about when would be the actual deadline for Congress to act, and House Majority Leader Steny H. Hoyer told reporters that he would be asking Mnuchin for an implementation delay.

The Maryland Democrat said he was planning to introduce a resolution of disapproval regarding the Treasury Department’s December decision.

“The issue is whether or not as a result of introducing it we can act after the 17th to preclude the sanctions or to retreat from the sanctions,” Hoyer said.

“I would hope he can give us an extension to February 28, so that Congress — Financial Services has jurisdiction, Foreign Affairs has jurisdiction — so that both of those committees could review it, perhaps have hearings on it and make recommendations,” he said.

Lindsey McPherson, Patrick Kelley and David Lerman contributed to this report.