A Republican senator on Sunday warned against rushing a vote on a GOP bill to repeal and replace the nation’s health care law, saying both parties deserve a chance to fully debate the bill and propose changes after it was drafted in secret.

“The Senate is not a place where you can just cook up something behind closed doors and rush it for a vote,” said Sen. Marco Rubio, R-Fla. “So the first step in this may be crafted among a small group of people, but then everyone’s going to get to weigh in.”

His comments come as Senate Republicans are working hard to finalize legislation to replace the Affordable Care Act, also known as Obamacare, without a formal, open drafting session. Senate Majority Leader Mitch McConnell, R-Ky., has said he hopes to bring a bill to the floor for a vote within the next two weeks.

But Rubio said he believes the process could take longer and urged the Senate to slow down. These are striking comments from a Republican senator whose party is seeking to push through legislation without the help of Democrats.

President Donald Trump has been eager for quick action, although in a closed-door luncheon with 15 GOP senators last week, he described a House-passed bill as “mean.” Trump said he wanted the Senate version to be “more generous,” according to congressional sources.

“It is going to take days and weeks to work through that in the Senate,” Rubio said on CBS’ “Face the Nation.”

The bill passed by House Republicans last month would phase out in 2020 a Medicaid expansion to additional low-income people. The Congressional Budget Office has estimated the House bill would cause 23 million people to lose insurance over a decade and leave many sicker and older consumers with much higher costs.

Hoping to doom the GOP effort, a consumer health group said Sunday it was launching a $1.5 million campaign aimed at pressuring five Republican senators in the closely divided chamber to vote against the bill. It was among several groups that in recent weeks have announced stepped-up efforts to oppose the bill.

Community Catalyst Action Fund said it will run television and radio ads beginning Monday. They are targeting Sens. Lisa Murkowski of Alaska; Jeff Flake of Arizona; Susan Collins of Maine; Dean Heller of Nevada; and Shelley Moore Capito of West Virginia.

“The Senate is working in secret and rushing to pass a bill,” said Robert Restuccia, executive director of the group. “We think it’s critical that Americans across the country understand what’s at stake for them and their families if the U.S. Senate passes this bill.”

Several of the senators being targeted have expressed some concern about the evolving Senate legislation or its process. All of them except Collins also represent states which expanded Medicaid under Obamacare.

Republicans hold a narrow 52-48 majority in the Senate, meaning the party can only afford to have two senators oppose the repeal and replace bill for it to pass with Vice President Mike Pence casting the tie-breaking vote. No Democrat is expected to support the repeal effort.

The ads seek to cast the GOP effort as having a negative impact on families and older Americans. The TV ad features a mother with a child with asthma who faces difficult choices between filling prescriptions or paying their mortgage due to rising premiums.

GOP senators have been divided over pivotal questions about dismantling and replacing chunks of former President Barack Obama’s health care overhaul. These include disagreements over phasing out the Medicaid expansion, easing some of the law’s coverage requirements and reshaping subsidies the statute provides to millions of individuals buying policies.

(AP)