Top members of President Donald Trump’s administration and Senate Republicans were upbeat about the progress on the Senate’s tax overhaul proposal Tuesday, even as there were signs of internal GOP conflict.

“Nothing is more important to the president’s economic agenda than tax reform and tax cuts,” Treasury Secretary Steven Mnuchin told reporters on Capitol Hill Tuesday. “We couldn’t be more excited about where we are.”

Mnuchin joined with senior Trump adviser KellyAnne Conway, an array of GOP senators and outside conservative stakeholders as the House Ways and Means Committee was working through amendments. The Senate Finance Committee is expected to release its own proposal later this week. 

“Just got out of the Finance Committee, putting final touches on the chairman’s mark. It’ll be introduced on Thursday. We’ll go through amendments in committee all next week, until we’re done,” Finance Committee member and Nevada GOP Sen. Dean Heller said.

“We’ll get a bill down to the floor, and do what the president wants us to do. That’s what the Finance Committee wants us to do, and that’s to make America more competitive, and also to make sure that the middle class has a tax cut,” Heller said, echoing the party line. “That’s what the Finance Committee is going to do.”

Democrats have noted several analyses of the measure that show middle class taxpayers being subject to tax increases, and are hammering the GOP for that. But Republicans can pass the legislation without any Democratic votes. 

But Republican unity is not a given. When Sen. Ted Cruz spoke at the event, he called for a roll-back of the individual mandate penalty for not purchasing health insurance under the 2010 health care overhaul law, saying it would free up money to put toward the tax cuts. 

“We’ve got to achieve consensus. We haven’t done that yet, but I believe we’ll get there,” the Texas Republican said.

Cruz, who is not a member of the Finance Committee, also pointed to the potential that people with significant property and state income tax burdens could essentially face tax hikes due to the eliminations of deductions.

“In the House plan right now the business side is terrific, but there are some taxpayers who are losing exemptions, particularly in some high-tax states, particularly New York and California, that could conceivably be paying higher taxes,” Cruz said. “I think that is a mistake.”

However, Cruz’s proposed solution for filling that hole would re-open the debate over repealing the health care law as part of the tax debate, potentially complicating the Senate vote count.

Sen. Lisa Murkowski told reporters that adding issues related to the health care law to a tax package would make “a complicated discussion even more complicated,” but the Alaska Republican said she would “wait and see” about the Senate’s tax bill.

Conway, asked about the health care mandate, was largely deferential to the tax-writers on Capitol Hill.

“We respect the fact that a process is ongoing, that is the job of the legislature, both chambers, to go ahead and follow through with their work,” Conway said. “The president has made very clear what his priorities are for both health care reform but also tax cuts and job security.”

She also insisted Trump would continue to welcome Democratic support.

“The question as to whether tax cuts and tax overhaul will be bipartisan is really at this point a question for the Democrats, not the Republicans,” Conway said.