The teachers union of Barrington Unit District 220 declared an impasse early Thursday in its federally mediated contract negotiations with the board of education.
The declaration initiates the legal process to allow a strike, which could occur Wednesday, Feb. 20 at the earliest.
The Barrington Education Association, which represents the district's nearly 700 teachers, made the declaration shortly after a negotiation meeting Wednesday night.
"As of last night, there wasn't significant enough progress for us to avoid an impasse," BEA President Melanie Collins said Thursday.
The impasse came as a surprise to school board President Brian Battle, who earlier this month had expressed optimism about the progress of mediated negotiations.
"We really don't know why they decided to declare impasse," Battle said.
The impasse means that the union and the school board now have seven more days to agree on a contract before each is required to submit their last and final offers to the Illinois Educational Labor Relations Board.
If no agreement is reached in the seven days after that, the labor relations board will publish both sides' final offers for public review on Wednesday, Feb. 6.
If there's still no agreement within 14 days of that posting, the union can call a strike. Teachers already voted in October to authorize a walkout.
District officials stressed that neither Thursday's impasse declaration nor any other step along the way guarantees a strike.
And Collins said the union, too, hopes a strike will not be necessary.
"The BEA's intent is to do everything we can to avoid a strike," she said. "Our intent is to do everything possible to get a contract settlement, and we will schedule as many meetings as necessary to make that happen."
According to the union's website, the two sides are scheduled to meet next on Jan. 30.
The union and school board have been negotiating since March toward a new contract to succeed the one which expired at the end of August 2012. A federal mediator became involved in December.
The last time a teacher walkout occurred in District 220 was in 1980.