EVERETT — Union leaders presented 33,000 Boeing Machinists with the latest contract proposal aimed at ending an ongoing strike that will enter its eighth week as of Friday.

Leaders with the International Association of Machinists and Aerospace Workers union announced the proposal Thursday afternoon, and recommended members approve the deal.

“It is time for our members to lock in these gains and confidently declare victory,” the union said in a statement.

The latest proposal includes a 38% general wage increase over the next four years for its 33,000 members. This will be the third offer for IAM members to vote on since negotiations began last spring. Union members voted overwhelmingly against the first offer, leading to the strike that began on Sept. 13.

Last week, 64% of Machinists rejected a contract offer that called for a 35% increase.

Members are expected to vote on the proposal Monday. A simple majority of yes votes would end the strike and send Machinists back to work. A no vote would extend the strike, which has cost Boeing at least $5.5 billion in its first six weeks, the New York Times reported.

Trevor Knightley, an electrical installer who works at the Everett plant, said Thursday he thinks it could be a good offer. He’s not sure how other members will vote.

“In my personal opinion, and my professional opinion, I think it is a good offer and I think it will be something our membership will vote for, but I don’t know how they’ll vote,” Knightley said. “I’ll tell you the honest truth, I’m getting a lot of mixed reviews on how people feel. I’m getting the yays and the nays.”

In a statement Thursday, Boeing said the new proposal includes a $12,000 ratification bonus, up from $7,000 proposed in the previous offer.

Other details include a commitment to build Boeing’s next new airplane in the Puget Sound region. The statement did not specify if that would be in the company’s Everett or Renton plants.

Currently, the Everett plant, featuring 17,000 union Machinists, is responsible for building the 767 and 777 planes.

The latest deal also includes upgrades to workers’ retirement plans. Whether or not that’s enough to satisfy a simple majority of IAM workers, remains to be seen.

Even before the latest rejection of a contract proposal on Oct. 23, many union workers said their pension was the biggest item “the company took from them.”

In 2014, the union narrowly voted to forego pensions after Boeing floated working on a new version of the 777 out of state.

The new proposal comes as talks resumed Tuesday, with assistance from acting Labor Secretary Julie Su.

Herald writer Will Geschke contributed to this report.

This is a developing story. Check back for updates.

Michael Henneke: 425-339-3431; michael.henneke@heraldnet.com; X: @ihenpecked.