MANDATA - Line Mountain School District teachers are preparing to strike after the latest bargaining session with the school board ended without a new contract, according to the union's chief negotiator.

Mark McDade, of the Pennsylvania State Education Association, said a date to strike hasn't been set and that it could occur either this school year or next school year. He said the state Department of Education would determine how many days the strike could last.

"It appears to be imminent," McDade said Tuesday.

The union voted earlier this year to authorize use of a strike.

Troy Laudenslager, school board president, said when reached for a response that he was unaware of a potential strike, but that it comes as no surprise.

He said he expects union members will target each of the school board's nine members individually.

"We're expecting to be demonized, singled out. They'll put as much heat on us as they possibly can," Laudenslager said.

"That's just one of the tactics they're pulling right out of the playbook. You've got to have thick skin," he said.

Representatives of both the union and school district met Monday for nearly four hours. Four proposals were exchanged from both sides, McDade said. The district adjourned the session with no agreement.

Another bargaining session hasn't been scheduled, but the school district is requesting that state mediator Jack Yanchulis be present. Laudenslager said a scheduling conflict kept him from Monday's session.

Neither McDade nor Laudenslager would address in detail what issues remained sticking points.

McDade said the school district is playing to win rather than negotiating toward finding middle ground. The teachers union was willing to meet some district demands, but he said the district made no attempt to meet the union's.

"I don't know how you can bargain with a group of people who define negotiations as a winner-takes-all approach," McDade said.

Laudenslager said the district made multiple proposals "outside the box" to acquiesce to union demands.

"If they strike, that's their call," he said.

Line Mountain teachers have been working on an expired contract since June 2012. The union has previously threatened to strike and will continue "working to the rule," a position the union adopted Sept. 30, meaning teachers work during the contracted 7 1/2 hours and nothing more.

Teachers received an annual 3-percent raise in the expired pact.

About 100 teachers picketed a board meeting in March, and half returned to a second meeting that month to stand together in silence during the meeting.