As Senate Republicans push full steam ahead on their final attempt to repeal Obamacare, several key governors came out on Tuesday against the bill crafted by Sens. Lindsey Graham (R-SC) and Bill Cassidy (R-LA).

Independent Alaska Gov. Bill Walker and Republican Nevada Gov. Brian Sandoval were among ten governors to sign a letter opposing the bill. Walker’s opposition could influence Sen. Lisa Murkowski’s (R-AK) vote, while Sandoval’s complaints about the bill buck Sen. Dean Heller (R-NV), who co-sponsored the bill.

In the letter, the governors called on senators to abandon the Graham-Cassidy bill and pursue bipartisan legislation to stabilize the health insurance market instead. They also urged lawmakers to use regular order to craft legislation, rather than follow the rushed process GOP leaders are using in their last-ditch attempt to repeal the Affordable Care Act.

“Only open, bipartisan approaches can achieve true, lasting reforms,” the governors wrote.

Several other Republican governors signed the letter as well, including Ohio Gov. John Kasich, Massachusetts Gov. Charles Baker, and Vermont Gov. Phil Scott.

Walker, the Alaska governor, expressed concern Tuesday morning about how the Graham-Cassidy bill would impact Medicaid, but the letter later confirmed his opposition to the bill. Murkowski, who has opposed other recent attempts to repeal Obamacare in the Senate, is again a key lawmaker to watch as Republicans search for the votes needed to pass the Graham-Cassidy bill. As of Tuesday morning, she was still assessing the bill.

Walker’s opposition to the bill came after the White House called the Alaska governor as part of an effort to garner more support for the Graham-Cassidy bill, according to a vice presidential pool report citing comments from Mike Pence and Graham.

Republican Maryland Gov. Larry Hogan issued a statement later on Tuesday declaring his opposition to the Graham-Cassidy repeal bill and instead calling for a bipartisan fix in the Senate.

“Unfortunately, the Graham-Cassidy bill is not a solution that works for Maryland. It will cost our state over $2 billion annually while directly jeopardizing the health care of our citizens. We need common sense, bipartisan solutions that will stabilize markets and actually expand affordable coverage,” he said in a statement.

Read the letter below:

This post has been updated.