(JEFFERSON CITY, Mo., AP) — Republican state senators took steps Thursday to try to curb the governor’s power to fill vacancies in state agencies and force him to call special elections for empty seats the Legislature, in what was the Missouri Senate’s first action of the year.

The chamber gave preliminary approve to a measure that would limit the amount of time temporary leaders can lead agencies. It would also force the governor to call a special election to fill vacant seats in the Legislature within 30 days.

The measure comes amid Republicans’ increased frustration over how long Democratic Gov. Jay Nixon allows agencies to be led by acting directors and over a vacant House seat that’s been empty since June.

That House seat is in a reliably Republican district and an election could give the GOP a veto-proof two-thirds majority in that chamber. Nixon has not said why he hasn’t called a special election, responding only that he’ll do so at the appropriate time.

As far as filling agency vacancies, Nixon has said it takes time to find the right people to be permanent directors. Permanent directors chosen by the governor require Senate confirmation, while acting leaders do not.

“This legislation will ensure timely appointments and empower the people to fill vacancies in elected offices at the earliest opportunities,” said sponsoring Sen. Bob Dixon, R-Springfield.

Under the measure, an acting director could lead an agency for no more than 120 days.

Missouri governors select directors for nearly a dozen departments. Two of those departments currently lack a permanent director, after Nixon recently made two other appointments requiring Senate confirmation. One of those appointments — Gail Vasterling to lead the health department — was cleared by the Senate on Thursday. Vasterling had been acting director since December 2012.

The Revenue and Social Services departments are now the only agencies without a permanent director. John Mollenkamp has been acting revenue director since the previous director’s resignation in April amid concerns over the handling of documents for concealed gun permits and driver’s licenses. Brian Kinkade has led the Social Service Department since May, which is the second time he has held that position for Nixon.

Dixon’s bill would also force the governor to call a special election to fill vacant seats in the Legislature and statewide offices within 30 days. That election would not need to actually take place during a specified time frame.

Republicans have criticized Nixon for not calling an election to fill now-U.S. Rep. Jason Smith’s state House seat that has been vacant since June. Two other House seats and one Senate seat are also vacant.

The legislation endorsed Thursday would also crack down on the number of people serving past their expired term on state regulatory boards and commissions. Missouri law currently allows members of those boards to serve until their successor is chosen; the bill would let them serve only 60 days beyond their term’s end date.

The move follows a report this month by Republican State Auditor Tom Schweich that showed that 63 percent of board members within the Department of Insurance, Financial Institutions and Professional Registration were serving beyond their term’s expiration.

Nixon said it has been difficult to fill slots when the number of state boards and commissions keeps growing and with the difficult Senate confirmation process.

“I’ll just have to say it that it gets, I believe, harder and harder to coax, shall we say, folks into being willing to do that,” he said.

Senate President Pro Tem Tom Dempsey, R-St. Charles, said he expects the Senate to take up a proposed constitutional amendment next week that would let the lieutenant governor fill vacancies in state government if the governor does not nominate a person for the position within 90 days. Missouri currently has a Republican lieutenant governor.

Dixon’s measure needs one more Senate vote before moving to the House.