AUGUSTA, Maine — Gov. Paul LePage followed through on his vow to veto a compromise $6.3 billion two-year budget sent to him June 13 by the Legislature. The Republican governor issued his veto letter Monday afternoon.

Democrats, who hold majorities in both chambers of the Legislature, responded that if the Republicans who voted to enact the budget hold form on Wednesday, the veto will be overridden.

In his veto message, LePage said the budget harms students and elderly Mainers. He also repeated his complaint that the state’s “welfare” spending cuts too deeply into other budget areas.

“This veto is not one done lightly,” he said. “When I submitted a balanced budget, I knew there would be areas of concern for many legislators. That is why we had nearly six months to work together and find a solution that would have made hard decisions while still protecting our most vulnerable. It was an opportunity for our state to do something great, to make real changes for the better. Unfortunately, it was an opportunity missed.”

The veto sets the stage for crucial override votes Wednesday in the Maine House and Senate, both of which passed the budget with at least two-thirds majorities before sending it to LePage. If either chamber fails to reach the two-thirds vote threshold, the veto will be sustained, leaving the state without a budget for the two-year fiscal cycle that begins July 1.

Without a budget, all but essential services of state government would shut down, repeating a 1991 scenario that Democrats and Republicans in the Legislature have said they want to avoid.

House Speaker Mark Eves, D-North Berwick, said he sees no reason for the 23 House Republicans who voted for the biennial budget earlier this month to switch now, and that recent behavior by LePage — namely his personal attacks last week on Sen. Troy Jackson, D-Allagash — could alienate even more Republicans.

“We’re urging our Republican colleagues to stick with the votes that they took and in doing so prevent a state shutdown and prevent a massive property tax increase to Mainers,” Eves said. “The antics of the governor make it easier for Republicans in the Legislature to break with the governor when he says these outrageous things.”

Sen. Michael Thibodeau, R-Winterport, congratulated LePage for his veto.

“Instead of asking our elected representatives to cut spending, we are asking the people of Maine for more of their paychecks to pay for oversized government programs,” said Thibodeau in a prepared statement. “I believe this veto gives us a chance to make the budget of Maine families a priority over the budget of state government.”

LePage — who objects to temporary sales, meals and lodging taxes included in the budget — last week told Dirigo Girls State delegates that a “two-week shutdown would be preferable to two years with this budget.”

On Thursday, the governor proposed a temporary 60-day budget in the form of the continuing resolutions used by Congress to pay for ongoing government functions while he and legislators negotiate a new budget deal. Maine Attorney General Janet Mills, a Democrat, said such a plan would violate the Maine Constitution, and Democratic legislative leaders — who believe they have enough votes to override the budget veto — showed no interest in the plan.

Michael Cianchette, LePage’s chief legal counsel, differed with Mills’ interpretation. He said a short-term budget that does not call for state government to spend more than it takes in would not violate the Maine Constitution and could be presented as an emergency bill, which would take effect immediately if it passes with two-thirds support of the House and Senate and gains the governor’s signature.

Asked by reporters about another path to a budget that the governor supports, Eves reiterated that it will be a moot point Wednesday when the Legislature takes up the veto votes.

Rep. Michael Carey, D-Lewiston, a member of the budget-writing Appropriations Committee, agreed and said the current impasse between the executive and legislative branches could have been avoided.

“I wish the administration had engaged more closely through the process,” said Carey. “It was a long bipartisan process that really worked well.”

In his veto letter, LePage laid out his priorities for reform at all levels of government.

“Our overly generous welfare programs can be reformed, cutting waste, fraud and abuse,” he wrote. “We can rethink our subsidies to cities and towns — Lewiston and Auburn are already doing much together and could do more. I have told everyone where the efficiencies lie in Waterville, Winslow, Oakland and Fairfield. And often we forget that our counties can be partners to increase efficiencies and reduce cost in local government. But we need to start somewhere, and that somewhere starts in Augusta.”

The Legislature’s 13-member Appropriations Committee, after lengthy overnight negotiations, unanimously endorsed the compromise budget early June 8. The budget compromise temporarily raises the state sales tax from 5 percent to 5.5 percent and meals and lodging taxes from 7 percent to 8 percent through June 30, 2015. It restores about 65 percent of the $200 million in municipal revenue sharing that LePage proposed suspending as part of the two-year budget plan he introduced in January.

The Legislature’s budget also makes major changes to LePage’s original human services and education funding proposals. The governor used his veto letter to again criticize lawmakers for using the budget to undermine his school reform agenda.

The House voted 102-43 to enact the budget. The Senate voted 25-10.

As of Friday, LePage had vetoed more than 30 pieces of legislation this session. The Legislature has sustained every one of them for which an override vote has been taken, although more than a dozen will be subject to legislative votes Wednesday.

The governor concluded his veto letter with a call for new negotiations with Democratic legislative leaders, with whom he has clashed often but negotiated rarely this session.

“There are some good pieces in this budget — I recognize that,” he wrote. “Those pieces can be a starting point for us to go back to the table and do more. I have extended an offer to legislative leadership that can avoid a shutdown in the near-term and give us time to eliminate these sales, meals and lodging tax increases. However, while these increases remain in the budget, I cannot support it. Mainers cannot afford it and with them I will stand.”

BDN staff writer Christopher Cousins contributed to this report.