The union representing Hawaiian Airlines flight attendants said today that members have overwhelmingly voted to authorize a strike.

The Association of Flight Attendants-CWA said that the tally showed a 99.9% vote to authorize a strike, with 95.1% participating.

“This historic strike vote takes our contract fight to an entirely new level,” said Master Executive Council president Sharon Soper in a news release. “Hawaiian Flight Attendants are sending an emphatic message to management: Delay is not acceptable; we demand the contract we deserve because we earn it every day. We are safety professionals, and management must acknowledge our worth. Hawaiian is profitable and the time has come for Flight Attendants to share in what we have helped create.”

According to the union, Hawaiian flight attendants are paid less than their counterparts in the industry, yet are based in cities with the highest costs of living in the nation, and are also renowned for their safety record and level of service.

Negotiations began in January 2017, and are overseen by the National Mediation Board, which follows a collective bargaining process. While Hawaiian Airlines pilots negotiated a new contract that year, flight attendants continue to face labor unrest, the union said.

Hawaiian Airlines issued a statement, saying that a strike is illegal until the National Mediation Board releases both parties from mediation and a cooling off period expires, neither of which has occurred.

“Having said that, we understand what this vote symbolizes, and we share the sentiment of frustration with the slow pace of these negotiations that it conveys,” said the airline in a statement. “There is no doubt that our flight attendants deliver the best hospitality in the industry, and we are determined to reach an agreement that recognizes their contributions to our success with increases in compensation while ensuring that our company can remain competitive and continue to grow. We have been working with a federal mediator for a year now and we remain committed to reaching an agreement through good faith negotiations under the mediator’s guidance.”

Over the last six months, Hawaiian Flight Attendants have picketed at Honolulu and Los Angeles airports, including a weeklong protest held earlier this month during the airline’s 90th birthday.

The lack of progress could lead to the board declaring that negotiations are deadlocked, the union said, and releasing both parties into a 30-day “cooling off” period leading to a strike deadline.

The AFA has a trademarked strike strategy known as CHAOS or Create Havoc Around Our System. With CHAOS, a strike could affect the entire system or a single flight, the union said. The union decides when, where, and how to strike without notice to management or passengers.