DES MOINES — The leader of one of the three unions representing state workers confirmed Monday that the State Police Officers Council has reached a tentative agreement with state negotiators on a new two-year collective bargaining agreement.

Iowa state trooper Mark Bowlin said the roughly 600 members will hold ratification votes Tuesday and Wednesday, when details will be discussed of the contract that will run from July 1, 2013, through June 30, 2015. He declined to discuss details of the tentative deal finalized Friday, saying “we’d like a chance to explain it to our members first and then be able to tell everybody else.”

Earlier Monday, Gov. Terry Branstad told reporters during his weekly news conference that he believes state negotiators are close to reaching a voluntary agreement on a new collective bargaining contract with one of the three state employees bargaining units.

“We’re very hopeful that one of those contracts may well be finalized very soon,” he said.

The governor declined to identify the union or provide any other details during his weekly news conference, saying, “I think it would be inappropriate for me to comment until the rank-and-file members have had a chance to vote on the ratification.”

Last fall, state officials exchanged opening bargaining positions with representatives from the state police union, American Federation of State, County and Municipal Employees and Iowa United Professionals, with the state seeking a freeze on across-the-board and “step” wage increases.

State negotiators also proposed that all state employees pay a greater share of their health-insurance costs — including a requirement that workers enrolled on single plans with no premium would begin paying 20 percent of the insurance cost for the new contract period. The state police union sought a 2 percent salary increase beginning in July 2013 and another 2 percent boost in July 2014 in its initial offer.

Branstad brought up the topic of contract talks in defending actions by his administration to pay bonuses and moving expenses to some state department directors and to hire back state employees who had been fired for misconduct but returned to the job after winning appeals through the grievance procedures.

Responding to a Des Moines Register report indicating that at least 33 state employees who have been fired for misconduct during the past five years are back on the state payroll, the governor said “it is a concern.” But he noted that “some of management’s rights have been basically bargained away over years” and the state is obligated to “abide by decisions made by outside arbitrators and others” in cases of discipline and discharge.

Branstad said state negotiators are trying to address work place rules in the current contract talks. Overall, he said, “we have a lot of dedicated, hard-working employees that follow the rules and do things right.”

The governor also defended pay bonuses for top state agency heads that came under fire from Homan and other AFSCME officials last week. For instance, he said, Debi Durham, director of the state Economic Development Authority, was paid bonuses because she took on the responsibilities of two state jobs and was denied enough “appropriate” compensation by lawmakers. He also said there was confusion over moving expenses that were paid to compensate costs not as bonuses.

“Many of the people that I asked to become department heads in state government took significant pay cuts to take on those positions,” the governor noted. “And they received no increase in the first year that I was governor while state employees in the union contract did get increases.”

On Friday, AFSCME President Danny Homan and other top union officials accused the governor of “demonizing” state workers and employing a double standard where he wants to freeze their wages and raise their health-insurance costs while handing out financial “goodies” to his managers and corporations from the state’s surplus. Homan said state employees are being unfairly attacked and being asked to make major concessions at a time when the GOP governor is paying “massive” bonuses to department directors and providing liberal tax credits to businesses pledging to create jobs in Iowa.