In a stunning admission, a White House official told Politico, “We really aren’t sure what the impact will be” of Senate Republicans’ latest effort to repeal and replace Obamacare.

The concession from an unnamed White House official comes as Senate Republicans are facing fierce criticism from industry and trade groups, governors and other state officials and health policy experts for the rushed process they are are using to get the new Graham-Cassidy repeal bill through the Senate before the Sept. 30 deadline for passing it with a simple majority vote.

Both Democrat and Republican House members have expressed concern over the process of crafting the legislation, especially efforts to push for a vote before the Congressional Budget Office has a chance to make full projections on the cost of the bill and the numbers of people who would lose insurance coverage.

In its letter to Senate leadership, the group of governors — whose opposition alarmed the White House, according to Politico — asked senators to abandon the Graham-Cassidy bill and work on crafting bipartisan legislation that would stabilize insurance markets. They urged senators to use the regular order method of writing a bill, rather than rushing the process.

The Graham-Cassidy bill would repeal much of the Affordable Care Act and would transform Medicaid and Obamacare subsidies into block grants controlled by individual states.