AUGUSTA — Gov. Paul LePage threw his support on Thursday behind the American Health Care Act, releasing letters asking U.S. Sens. Angus King and Susan Collins to back it and lending a prominent voice to the endangered national Republican health care plan.

LePage has spent considerable time in Washington, D.C., lobbying members of Congress to alter the Affordable Care Act repeal-and-replace bill, which is due for a vote Thursday night in the U.S. House of Representatives and is struggling under the weight of conservative opposition.

But LePage struck a new tone in identical letters that were dated on Wednesday to Collins, a Republican, and King, an independent who caucuses with Democrats.

“I’m urging you to join us in the effort to repeal, replace and reform ObamaCare once and for all,” wrote LePage. “The people of Maine elected you to a place on the national stage, but they expect you to represent them — not the residents of some other state. Their economic future, as well as the long-term financial stability of our state, is at stake.”

Until now, LePage has voiced opposition to the proposed health care plan. Earlier this month, he sent a letter to U.S. House Speaker Paul Ryan which said of the bill, “early signs do not look encouraging.” LePage called for a “truly conservative, free-market replacement” that ends previous Medicaid expansion for non-disabled adults and allows states latitude to use Medicaid dollars — including determining eligibility and defining benefits — as they see fit.

LePage argued in the letters to Collins and King that Medicaid expansion in 2002 created “tremendous financial problems” in Maine, including a $750 million debt to hospitals which has been paid off under the administrations of LePage and Democratic Gov. John Baldacci.

LePage, who has consistently called for an end to federal incentives for states to expand their Medicaid programs, said continuing to allow non-disabled adults without children into the program would cause an estimated 100,000 Mainers to drop their private insurance and enroll in Medicaid. The governor has yet to provide data that clearly supports his claim.

The American Health Care Act is an evolving document and according to news reports was still undergoing revisions Thursday afternoon, just hours before the House vote.

Adrienne Bennett, a spokeswoman for the governor, said while the letters to the senators offered full-throated support for repealing the Affordable Care Act and enacting the American Health Care Act, “there is more work to do” on the latter.

Gov. Paul LePage