Tens of thousands of striking Boeing machinists will vote Monday on whether to accept a contract offer that could end their work stoppage after seven weeks.

According to the International Association of Machinists and Aerospace Workers (IAM), the union that represents 33,000 Boeing workers in Washington, Oregon and the United States, the new offer includes higher wage increases and an increased ratification bonus that will give each worker $12,000 would if the union agrees to the deal California.

The ongoing standoff has strained the finances of both sides. Union members received $250 a week from a strike fund starting the third week of the work stoppage. This compensation represents a significant pay cut for many employees.

Boeing and its shareholders have lost about $5.5 billion since the strike began in September, according to an estimate last month by the Anderson Economic Group. Boeing shares have plunged 40% this year but have gained slightly over the last month.

Union members strongly opposed two previous proposals from Boeing, but the latest offer represents the best deal the workforce is likely to receive, the union said in a public letter to members Saturday.

“This is truly the time to lock in these gains and work to build more in future negotiations,” IAM President Jon Holden and the union’s bargaining committee told members. “Allow yourself to achieve this victory and be proud of your sacrifice.”

The proposed contract would provide for a 38% increase over the four-year term of the contract, increasing the cumulative 35% increase included in a previous offer that was overwhelmingly rejected by workers in a vote two weeks ago. The employees had initially demanded a cumulative wage increase of 40%.

The proposal also calls for an increase in Boeing's contribution to a 401(k) plan, but declines to address workers' demands to reinstate the company's defined pension. Under a contract ratified by the union in 2014, workers lost a traditional pension plan.

Nearly two-thirds of union members rejected the latest contract offer in a vote last month. The result followed the overwhelming defeat of an earlier proposal in September, which was rejected by more than 90% of union members.

“It is time for us all to come together again and focus on rebuilding the company and delivering the best aircraft in the world,” Boeing CEO Kelly Ortberg wrote in a memo to employees on Friday. “Many people depend on us.”

A majority of union members is required to approve the contract offer. If workers ratify the agreement, they could return to work as early as Wednesday, the union said.

“The decision to end this strike is exactly where it needs to be – in the hands of the members,” Holden and the bargaining committee said in their public letter.