More than 100 lawmakers urged Starbucks to resume bargaining talks with Workers United, the union representing the coffee giant’s baristas, in letters sent to CEO Brian Niccol on Monday.

The two letters, from the Congressional Labor Caucus and a group of senators led by Sen. Bernie Sanders, I-Vt., come as the union threatens a strike in 25 cities starting Thursday. That coincides with Starbucks’ Red Cup Day, one of its biggest sales days of the holiday season.

“It is clear that Starbucks has the money to reach a fair agreement with its workers,” the Senate letter, signed by 26 lawmakers, reads. “Starbucks must reverse course from its current posture, resolve its existing labor disputes, and bargain a fair contract in good faith with these employees.”

A second Congressional Labor Caucus letter is signed by 82 lawmakers.

The lawmakers argued the coffee giant has the resources to increase workers’ pay and benefits, citing Niccol’s $95 million compensation since his hiring. The company said $90 million of the compensation package was in the form of stock awards to cover equity Niccol left behind at Chipotle when moving to Starbucks to take the CEO role.

Last week, Workers United said its strike authorization vote won a 92% approval from its members. If the union decides to strike, it would be open-ended. Workers United is pushing for improved hours, higher wages and the resolution of hundreds of unfair labor practice charges against the company.

The two parties are not in active contract talks after discussions fell apart late last year. Starbucks and the union entered into mediation in February, and hundreds of barista delegates voted down the economic package Starbucks proposed in April.

Both sides have pointed blame for failure to reach a bargaining agreement at the other party and say they’re ready to negotiate.

Workers United, which began organizing at Starbucks in 2021, says it now represents more than 12,000 workers across more than 650 stores. The company last week told CNBC that the union only represents 9,500 workers at 550 cafes.

Starbucks Workers United spokesperson Michelle Eisen said in a statement last week, “We want Starbucks to succeed, but turning the company around and bringing customers back begins with listening to and supporting the baristas who are responsible for the Starbucks experience. If Starbucks keeps stonewalling, they should expect to see their business grind to a halt. The ball is in Starbucks’ court.”

In response to the strike vote results last week, Starbucks said it will be ready to serve customers across its nearly 18,000 company-operated and licensed stores this holiday season.

“As everybody knows, Starbucks offers the best job in retail, including more than $30 an hour on average in pay and benefits for hourly partners. Workers United, which represents only 4% of our partners, chose to walk away from the bargaining table. We’ve asked them to return—many times. If they’re ready to come back, we’re ready to talk. We believe we can move quickly to a reasonable deal,” Starbucks spokesperson Jaci Anderson told CNBC in a statement Monday.

In a letter to workers addressing the strike authorization vote last week, Sara Kelly, chief partner officer at Starbucks, echoed the belief that an agreement could be reached swiftly.

“For months, we were at the bargaining table, working in good faith with Workers United and delegates from across the country to reach agreements that make sense for partners and for the long-term success of Starbucks,” Kelly said. “We reached more than 30 tentative agreements on full contract articles.”

“Our commitment to bargaining hasn’t changed,” she added. “Workers United walked away from the table but if they are ready to come back, we’re ready to talk. We believe we can move quickly to a reasonable deal.”

Reuters earlier reported on the letters from lawmakers.

— CNBC’s Amelia Lucas contributed to this report