Colorado Gov. Hickenlooper, a Democrat, and Ohio Gov. John Kasich, a Republican, joined a bipartisan group of 10 governors Tuesday in co-authoring a letter to Senate leadership that urges the rejection of the latest efforts to repeal the Affordable Care Act.

The letter, addressed to Senate Majority Leader Mitch McConnell, R-Ky., and Majority Leader Charles Schumer, D-N.Y., implores them to refuse consideration of the Graham-Cassidy-Heller-Johnson Amendment and calls on them to “renew support for bipartisan efforts to make health care more available and affordable for all Americans.”

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

The governors express their hope that bipartisan legislation, developed through an “open process,” can “bring stability and affordability to our insurance markets.”

“Legislation should receive consideration under regular order, including hearings in health committees and input from the appropriate health-related parties,” the letter states. “Improvements to our health insurance markets should control costs, stabilize the market, and positively impact coverage and care of millions of Americans, including many who are dealing with mental illness, chronic health problems, and drug addiction.”

The letter is additionally signed by Alaska Gov. Bill Walker, an independent; Montana Gov. Steve Bullock, a Democrat; Pennsylvania Gov. Tom Wolf, a Democrat; Virginia Gov. Terence R. McAuliffe, a Democrat; Louisana Gov. John Bel Edwards, a Democrat; Nevada Gov. Brian Sandoval, a Republican;  Massachusettes Gov. Charles D. Baker, a Republican; and Vermont Gov. Phil Scott, a Republican.

Hickenlooper and Kasich, an unlikely duo, have become well known for their bipartisan work on health care reform. Last month they debuted a health care proposal that called for immediate federal action to stabilize health care markets, an active federal and state partnership, and responsible reforms that preserve coverage gains and control costs.

Six additional governors signed onto the plan – a list identical to those who signed Tuesday’s letter, minus Scott and Baker.

Hickenlooper, Baker, Bullock and two other governors testified Sept. 7 before the Senate Committee on Health, Education, Labor and Pensions – on which Colorado Sen. Michael Bennet sits – regarding the proposal.