Flight attendants at Southwest Airlines have rejected a tentative contract agreement, with 64% of them voting against the proposed five-year deal, their union said on Friday.

The Transport Workers Union (TWU) Local 556, representing nearly 19,000 flight attendants, said in a statement “this proposed contract is not going to heal the hurt.”

Southwest’s flight attendants have been demanding higher pay and better work rules in the new contract. The previous contract came up for renewal in 2018.

Rivals American Airlines and United Airlines are also still negotiating with their flight attendants. Delta Air Lines‘ flight attendants are not unionized.

The TWU Local 556 said on Friday, “we will go back to the table to achieve the collective bargaining agreement that meets the needs of the hardest-working flight attendants in the industry.”

Southwest’s proposed contract included a 20% pay raise beginning next month and a 3% annual raise in 2025, 2026, 2027 and 2028.

The union had said that would have resulted in a 36% increase over the life of the contract for flight attendants at top of scale and up to 90% for other seniorities.

The tentative agreement also provided for paid parental and maternity leave with insurance coverage.

In the past two years, unions across the aerospace, construction, airline and rail industries have put up fights for higher wages and more benefits in a tight labor market.

Southwest has yet to reach a contract deal with its pilots.