Gov. Haley Barbour says he has executive authority to keep “critical” agencies operating if there’s no Mississippi budget when the new fiscal year begins next week.

Barbour’s comments came Tuesday, a day after he rejected a $5 billion budget compromise offered by House and Senate negotiators and refused to call lawmakers back for a special session.

Barbour may have the wrong interpretation of the state Constitution, said Rep. Robert Johnson, an attorney and one of the House budget negotiators.

Johnson, D-Natchez, said the constitution states that even without a budget, the state must continue to provide “essential services.” He said court action would be required for that to happen.

The start of the new budget year is July 1, and longtime lawmakers say this could be the first time in memory that the state begins a year without a spending plan for its agencies and programs.

Lawmakers missed deadlines to reach an agreement on the budget during the regular session that ended weeks ago. Now, Barbour has to call a special session, in which he sets the agenda, for them to adopt a state spending plan.

Barbour has refused to call a special session until negotiators eliminate language from a Medicaid compromise that prevents him from cutting the program. The no-cuts provision was meant to protect hospitals once a new multimillion-dollar tax is imposed.

Barbour was in Washington, D.C., on Tuesday, but he held a teleconference to discuss the state’s budget situation.

“I believe that we will have a budget by next Tuesday night,” Barbour said. “But if I’m wrong, and no agreement can be reached … the governor by his executive authority can make sure that critical services” could proceed.

He said those services include law enforcement, health and environmental protection programs.

Meanwhile, the lack of a budget has affected other programs, including public education, transportation and Medicaid, which have been unable to renew or honor contracts.

Barbour has pushed legislators to pass a $90 million tax on hospitals to help cover the cost of Medicaid, a government-funded health care program for the elderly, disabled and poor.

Mississippi hospitals were taxed to help pay for Medicaid for about a dozen years. In 2005, the federal government blocked Mississippi from using the tax as it was then structured.

Talks appear at a standstill.

“There’s a way to move forward. Call a special session,” House Speaker Billy McCoy, D-Rienzi, said Tuesday. “Let the process work.”

However, McCoy said the governor faces a challenge in the House.

“I don’t believe we could pass the governor’s Medicaid plan if we got on our knees and begged them,” he said.

McCoy criticized the governor for being out of the state while the budget remains unresolved. On Monday, Barbour was in Virginia campaigning for Republican gubernatorial candidate Bob McDonnell. Johnson said Barbour’s trip to the nation’s capital was for a news conference with other Republicans to discuss health care. Barbour is scheduled to speak at Republican fundraising events Wednesday in New Hampshire and Thursday in Iowa.

“It would be much more beneficial if he were here talking with us,” Johnson said.