An estimated 600 state employees got letters over the weekend telling them to pay their dues to the union or face possible dismissal.

Under a contract signed by Gov. John Baldacci last year, non-union state workers whose positions are represented by the Maine State Employees Association in bargaining talks are being required to pay half of the union’s regular dues for that negotiating work. That fee is about $4.50 a week. Based on that fee, the union stands to gain more than a half-million dollars annually under the requirement.

Non-union state workers have challenged the so-called “fair share” ruling in court, but have lost. The dues requirement has precedent in other states based on the fact that all workers in certain job categories benefit from union negotiations for salaries and health care.

Tim Belcher, director of the state employees union, estimated 600 people haven’t paid all or part of the dues owed, and the state is now sending out warning letters on the union’s behalf.

“I doubt that anybody’s going be dismissed,” Belcher said. “Certainly not unless they make a conscious decision to do so.”

The letter, sent out by the Baldacci administration, warns: “An employee who fails to comply with the terms of this lawfully negotiated Union Security article must be dismissed.”

Belcher said when the contract requiring the fair-share dues be paid was signed, there were about 2,400 state employees, who didn’t belong to the union. All but 600 have either paid their fair-share dues or become full-time union members. The fair-share fee is only supposed to be spent on negotiating and not on politics.

“They’re pushing it to the last minute,” he said. “The vast majority are going to pay … now that they’re getting this letter.”

Belcher said the 600 workers who owe money were being advised by the activist group unfairshare.org, which has told disgruntled workers to hold out to the end. It was a member of that group who sent notices to media outlets in Maine telling of the letters sent out by the state. On its Web site, the group outlines its strategy for those who received a letter from the state’s director of employee relations.

“We must make the current administration see that allowing forced unionism was a critical error. By caving in at the first extortion demands, you make it way too easy for the union to get what they want – your money. If you pay now, the administration never has to even say anything about firing employees. By fighting back and not paying until the very end (or not at all if that is your decision), you make it very painful to the administration. The exposure is very negative and does not help the public image of the governor.”

“Continue to defy the union, continue to speak out whenever you get a chance, and continue to let the media know what is going on,” the unfairshare.org site advises.

Ken Walo, director of the state’s Bureau of Employee Relations, who sent out the letters to non-paying workers, was out of his office on Monday and did not return a call.

Asked about the timing of the letters, so close to the Christmas holiday, Belcher said the workers brought it on themselves.

“They have had a year and half to pay. They didn’t have to put it off. We’re just moving ahead with the process, good, bad or indifferent,” he said.