A flyer distributed by the city's school bus drivers union warns parents against the city's conditions for new contracts.

The city and its school bus drivers union are each appealing to parents as they stake out their positions in a contract dispute that could cause a bus strike.

On Thursday, the city held a required meeting to explain its conditions for new contracts for school bus companies. One condition that it isn’t including, citing a 2011 legal decision, is a seniority clause guaranteeing that current drivers can keep their jobs even if the bus companies they work for do not win a new contract. That omission has drawn the ire of the bus drivers’ union, the Amalgamated Transit Union’s Local 1181, whose members authorized a strike over the issue when it first arose in 2011.

In a flyer handed out at the city’s meeting and being distributed by email, the ATU asks parents to lobby the city on bus drivers’ behalf. Telling parents that “there will be a stoppage to service to you,” the flyer warns parents that doing away with seniority protections could put children at risk.

Update: ATU 1181 President Michael Cordiello said through a spokeswoman today that the union is “exploring every option to avert a strike” but that it remained a likely possibility if the city does not cave.

“Please support us in our cause because you don’t want, ‘just anybody’ driving your children,” the flyer says. A few sentences later, in bold letters, it says, “Don’t put your child on an unsafe bus!”

Chancellor Dennis Walcott dismisses safety concerns in a letter to parents that students are taking home today.

“Please be assured that the bid also will include the same safety provisions that are in place today,” he writes, before outlining the city’s contingency plans for a strike. “Safety is our top priority and will continue to be so under new contracts.”

The Department of Education’s contingency plans are the same the city laid out over a year ago when union officials first said a strike over the seniority issue was “likely.” No interruption in bus service has taken place since.

A spokeswoman for the union, Regina Luzincourt-Eberhart, declined to provide more details about a possible strike but said that union leadership would address the issue at a press conference on Sunday.

Bus drivers are apparently also in the dark about whether they’ll be going on strike. Simon Jean-Baptiste, a veteran bus driver who once held office in the union, said today by phone that he hadn’t been notified of a work stoppage yet.