Starbucks illegally refused to negotiate at 21 recently unionized cafes in Washington state and Oregon, U.S. labor board prosecutors alleged in a complaint.

In a Tuesday filing on behalf of the National Labor Relations Board’s general counsel, the agency’s Seattle regional director wrote that Starbucks “has been failing and refusing to bargain collectively” in cities including Portland and Seattle, the coffee giant’s hometown.

Regional directors across the country have issued dozens of complaints accusing Starbucks of deploying illegal tactics such as threats and retaliation in an effort to defeat the union, Starbucks Workers United.

The new complaint is the first in which agency prosecutors accuse Starbucks of not bargaining fairly at multiple stores.

The union has filed other still-pending cases around the country accusing the company of failing to bargain fairly.

In an emailed statement, Starbucks said it will have shown up for more than 75 bargaining sessions at U.S. stores by the end of the year.

“We have come to the table time after time prepared to bargain in good faith, and continue to urge Workers United to uphold their promises to our partners by moving the bargaining process forward,” spokesperson Rachel Wall said.

The company has said repeatedly that it adheres to the law and that claims of anti-union activity are “categorically false.”

It has also filed its own pending claims with the labor board, accusing the union to failing to negotiate.

The new complaint says that Starbucks should be forced to negotiate regularly with the union, and to hold a meeting with interim Chief Executive Officer Howard Schultz and representatives of the union and the government, at which a notice about workers’ rights is read with employees present.

Complaints issued by NLRB regional directors are considered by agency judges, whose rulings can then be appealed to the labor board members in Washington, D.C., and from there into federal court.

NLRB members issued a ruling last month finding that Starbucks was illegally refusing to negotiate with the union at a mega-café in Seattle, a decision the company said it would appeal.

“This complaint proves what workers have been saying all along – Starbucks is dragging their feet at the negotiating table and refusing to bargain with us in good faith,” New York barista and Starbucks Workers United leader Michelle Eisen said in a statement Wednesday.

The union has prevailed in elections at around 270 of the company’s roughly 9,000 corporate-run U.S. cafes over the past year but remains far from reaching a collective bargaining agreement with the company at any of them.

Workers at around 100 stores participated in strikes earlier this month meant to increase the pressure on the company to negotiate.