The Washington State Labor Council called for the rally, saying it wants to show Boeing and state leaders it supports Machinists union members who voted last week to reject contract concessions Boeing said it needed to build the new 777X in Washington.
The council says the purpose of the "build it here" rally is to send a message that the Machinists deserve to not only build Boeing's next new plane in Washington but to share in the company's prosperity.
Over the weekend at the Dubai Airshow, three Middle Eastern airlines signed up to buy 225 of the large, fuel-efficient widebodies in deals worth $95 billion.
In the contract vote late Wednesday, The International Association of Machinists District 751 rejected the proposal with 67 percent of the votes. Union members who called for a no vote did so in protest of Boeing's push to end a traditional pension plan and increase their health care costs.
The deal would have exchanged those concessions for the long-term stability expected with the 777X line. Workers would have received a $10,000 signing bonus if they approved the deal.