The Legislature closed an $878 million hole in the budget through a combination of agency budget cuts and several revenue raising measures.

OKLAHOMA CITY — Gov. Mary Fallin signed a $6.8 billion spending bill on Wednesday that slashes the budgets of most Oklahoma agencies by about 5 percent over the objection of critics who say the measure may be unconstitutional and is likely to face a legal challenge.

Fallin signed the general appropriations bill, along with more than a dozen other measures approved by the Legislature in the last days of the legislative session that ended Friday.

The Legislature closed an $878 million hole in the budget through a combination of agency budget cuts and several revenue raising measures, including a $1.50-per-pack cigarette fee and a new 1.25 percent tax on vehicle purchases. Those two bills alone are expected to generate about $380 million annually, but critics say they violate constitutional provisions that prohibit revenue-raising measures from being passed in the final week of session and require tax increases to be approved with a three-fourth's vote of the Legislature.

"I'm highly confident that one or more parts of the revenue package that was used to patch this budget together are unconstitutional," said House Democratic leader Rep. Scott Inman, an attorney.

Lawmakers also diverted about $150 million from road and bridge projects; ended some tax exemptions for wind, oil and gas production; and raided dozens of agency revolving accounts to help balance the budget for the fiscal year that begins July 1. Fallin expressed concern that the use of one-time funds to close the budget gap will leave a hole of about $400 million in next year's budget.

"Developing a budget in this difficult fiscal and political climate is never easy," Fallin said in a statement. "This plan keeps our government from shutting down and, despite challenging circumstances, funds our core mission services."

The bill maintains flat funding or provides slight boosts in appropriations to 15 "core-mission" state agencies such as the Department of Human Services, Health Care Authority, prisons and public schools.

Fallin had proposed about $1.5 billion in her executive budget, including a sales tax on dozens of services that are currently exempt, as well as a fuel tax and other proposals, but the Legislature couldn't muster the bipartisan support needed to pass them.

Fallin also proposed an increase in teacher pay, which was strongly supported by the governor and the House, but faced too much opposition in the GOP-controlled Senate.