SEATTLE: Thousands of Boeing hourly workers voted in Seattle to authorise a potential labour strike if ongoing contract negotiations stumble, a union statement said Wednesday.

"We want the company to take our proposals seriously and bargain earnestly," said Jon Holden, President of IAM (International Association of Machinists and Aerospace Workers) District 751.

The initial vote - which passed nearly unanimously - provides advance notice to the union so members receive strike benefits if they vote to strike on September 12.

The local unit represents more than 30,000 people working at Boeing plants in nearby Renton, where the US aerospace giant's 737 is assembled, and also in Everett, where the 777 is put together.

A strike would freeze activity at both factories.

The two sides began talks in March on a new contract to replace an agreement that has been in place for 16 years. That contract expires at midnight on September 12.

Wednesday's vote comes before union members see a proposed contract. A second vote would be required on September 12 to strike if members reject the contract.

Boeing in a statement said: "We remain confident we can reach a deal that balances the needs of our employees and the business realities we face as a company."

Holden has demanded a "substantial" salary hike of at least 40 percent, as well as provisions for health care, retirement and job security.

He also called a hefty wage hike imperative after workers only received nominal cost-of-living support over the last eight years despite "massive inflation."

"We don't want to strike - but we're ready and willing to do so to bring home the best aerospace contract our members have ever seen," he added in a statement Wednesday.

At a Senate hearing last month, Boeing chief executive Dave Calhoun said workers "will definitely get a raise."

The union is also seeking assurances from Boeing that it will build its next new aircraft - expected around 2035 - in the Seattle region.

Holden has said certainty on the next jet being manufactured in the Pacific Northwest amounts to "job security for the next 50 years."

The IAM said talks have been largely moribund in recent weeks. The union sought a commanding turnout on Wednesday to send a strong message to Boeing.

The event was held at T-Mobile Park in Seattle, the stadium for the Seattle Mariners baseball team, which holds up to 48,000 people. The IAM also planned a parade of some 800 motorcycles.

"The purpose is to show Boeing your solidarity," the IAM said on the local unit's website.

"The factory will be quiet," the local said, adding it was sending a "message to take our proposals seriously and a reminder of what it would be like if our members choose to reject a substandard offer and vote to strike in September."

Boeing said it would allow employees to leave work early or arrive late to provide "reasonable" travel time on Wednesday.

"We respect and support the right of our employees to take part in the July 17 vote," Boeing said. "Partial time away from work will be excused and not counted for attendance purposes."

Striking workers are entitled to US$250 in weekly pay starting the third week of a strike.

The IAM has also sought at least one seat on Boeing's board of directors, but that demand is considered more of a longshot.

Besides the Washington workers, the IAM's W24 district, which represents 1,200 Boeing workers in Oregon, will also vote Wednesday.

In light of Boeing's current travails, the union wants to be able to bargain on any changes to quality management that could affect the production system.

"We never proposed those things in the past but it's our reputation, it's our jobs, it's our livelihoods," Holden said.

  - AFP