Nine months after talks began on a new teachers’ contract, the St. Paul Federation of Teachers — frustrated by a lack of district buy-in on several key proposals — is taking up talk of a possible strike.

Union President Mary Cathryn Ricker said Sunday that the federation’s 23-member executive board is expected to discuss on Monday whether to put a strike-authorization vote before the full membership.

Ricker would not state her position on the subject. She said that she wanted to share that with colleagues first. But the conversation comes as part of a monthly executive meeting dedicated in part to determining “where we are and where we need to go,” and in Ricker’s view, “we still haven’t made the kind of progress that we know we can make on issues like class size, staffing and early learning,” she said.

The district, for its part, has argued that efforts to rein in class sizes and expand preschool opportunities — while worthy goals — are outside the scope of the contract. Schools spokeswoman Toya Stewart Downey couldn’t be reached for comment Sunday.

Last fall, union leaders objected to a district move to take talks into mediation. Since then, the two sides have reached tentative agreements on 13 issues, and the union has ramped up efforts to remind district officials of the support it’s built within the community — first by presenting to school board members petitions with signatures from nearly 4,000 people backing federation goals and then by staging “walk-in” rallies with students and community members outside more than 50 schools on Jan. 30.

The rallies drew more than 2,000 educators, parents, students and community members, the union estimates, and took place the same morning that Superintendent Valeria Silva delivered her annual State of the District speech.

Last Thursday, the two sides met in a mediation session during which tentative agreements were reached on four bargaining points, the district said.

Ricker acknowledged that negotiators have made “incremental progress” on issues along the way. The mediator, too, she said, “was very happy with the things we discussed and how we discussed them.”

But, she said, the union wants to see progress on “our priorities,” and the question now, she said, as it has been in recent months, is “how serious we are” about making that push.