AUGUSTA, Maine — Gov. Paul LePage on Monday vetoed legislation to expand Maine’s Medicaid program, turning the focus back to majority Democrats to try and rally enough Republican votes to override it.

In his veto message, LePage wrote Maine has expanded Medicaid before — what he termed a “massive increase in welfare expansion” — and it hasn’t worked.

“Maine ran up massive debts to our hospitals as the system outgrew the taxpayers’ ability to pay,” he wrote, citing Maine’s $484 million debt to its hospitals. “At the same time, the uninsured population remained almost the same — 136,000 in 2001 to 133,000 in 2011. The only change was thousands upon thousands of Mainers leaving the commercial market for ‘free’ health care, expanding the welfare rolls from nearly 200,000 to 338,000.”

The House and Senate took final votes on the Medicaid bill, LD 1066, on Thursday. It passed in the House, 97-51, and in the Senate, 23-12. While both tallies included some Republican votes, they fell short of the two-thirds threshold needed to override LePage’s veto.

Expanding the state’s Medicaid program would provide coverage for about 50,000 adults without children who earn up to 133 percent of the federal poverty level, or $20,628 for a two-person household. The expansion would also prevent about 25,000 parents and childless adults from losing their Medicaid coverage starting Jan. 1, 2014.

In his letter, LePage warned lawmakers against accepting promises that the federal government will pay nearly all costs of expanding Medicaid over the next decade.

And he cautioned lawmakers against accepting compromise legislation that passed the House and Senate, under which Maine would withdraw from the Medicaid expansion after three years unless the Legislature decided to continue the coverage at that time.

“When we expanded in the 2000s, we were promised we could reduce eligibility if the goals were not met,” he said. “Now the federal government has tried to change the rules and lock our earlier generosity in place.”

Democratic legislative leaders reacted quickly, calling on Republicans to help them override the veto.

“Gov. LePage has made it clear that he will do whatever it takes to deny and delay health care to tens of thousands of Mainers, even if it means turning down jobs,” House Speaker Mark Eves, D-North Berwick, said in a statement. “Much needed health care and jobs are stake. We urge Republicans to join us in overriding this senseless veto.”

Senate President Justin Alfond, D-Portland, said it was “disappointing that the governor is making his choice to deny health care to tens of thousands of Mainers and deny economic opportunity in every corner of our state.”

In 2001, 10.6 percent of Maine residents didn’t have health insurance, compared to 9.7 percent in 2011, according to the United Health Foundation’s America’s Health Rankings. Nationally during that time, the percentage of people in the United States without insurance rose to 15.1 percent from 14.3 percent, according to the U.S. Centers for Disease Control.

While LePage has opposed expanding Medicaid, his administration in March began negotiating an expansion deal for Maine after a number of other Republican governors, including Jan Brewer of Arizona, Chris Christie of New Jersey and John Kasich of Ohio, agreed to accept the federal funds to expand Medicaid in their states.

The federal government ultimately denied a request from LePage’s health and human services commissioner, Mary Mayhew, to fully fund Maine’s expansion for 10 years; the law provides for full funding for three years.

“Maine must negotiate with Washington to ensure that our citizens and taxpayers are protected,” LePage wrote. “We need flexibility in our program to improve delivery and root out fraud and abuse. We deserve recognition for our earlier generosity. Quite simply, Maine can do better.”

The bill, which is sponsored by Rep. Linda Sanborn, D-Gorham, will return first to the House for an override attempt.

If the override attempt fails, Democrats have one legislative option left this year to pass Medicaid expansion.

A bill proposed by House Republican Leader Kenneth Fredette to form a study group to examine Maine’s Medicaid expansion options is still pending the Legislature’s Health and Human Services Committee.