The AARP, a major seniors group, on Thursday condemned Senate Republicans’ newly released Obamacare repeal bill and urged senators to vote against the legislation.

“We strongly urge the Senate to reject this bill,” AARP Executive Vice President Nancy LeaMond said in a statement. “As we did with all 435 Members of the House of Representatives, AARP will also hold all 100 Senators accountable for their votes on this harmful health care bill.”

As House Republicans floated their version of the bill to repeal and replace Obamacare in March, the AARP announced it would track their votes on the legislation and “communicate the results” to its members.

“This new Senate bill was crafted in secrecy behind closed doors without a single hearing or open debate—and it shows,” LeaMond said.

A so-called working group of 13 Republican senators worked behind closed doors to draft the bill, which they publicly released for the first time on Thursday. Their proposal would eliminate most of Obamacare’s subsidies and impose deeper long-term cuts to Medicaid than the House version of the bill.

LeaMond cited the latter as a major concern.

“The proposed Medicaid cuts would leave millions, including our most vulnerable seniors, at risk of losing the care they need and erode seniors’ ability to live in their homes and communities,” she said. “The Senate bill would hit millions of Americans with higher costs and result in less coverage for them.”