The leadership council for the union representing Boeing’s white-collar employees decided by 71 to 1 late Thursday to ask its 23,000 members for authorization to call a strike, officials said.

Members of the Society for Professional Engineering Employees in Aerospace (SPEEA) will also vote on Boeing’s contract offer, which the union’s negotiating team has recommended they reject.

If a majority of members approve the strike authorization, union leaders will have the power to call a strike at any time. It does not automatically mean the members will go on strike.

Ballots will be mailed out on Tuesday, the union said, and the votes will be tallied on Feb. 19.

For months, the negotiating teams for SPEEA and Boeing have been at an impasse over a new contract. The existing contracts for 15,550 engineers and 7,400 technical workers represented by the union expired Nov. 25.

Boeing’s latest contract offer provides for 5 percent average annual salary increases, no new increases in employee health-care contributions, and higher pension benefits for current employees.

The union has rejected Boeing’s final offer largely because it eliminates traditional pensions for new employees and increases pensions at a lower rate than the previous contract.

Sanjay Bhatt: 206-464-3103 or sbhatt@seattletimes.com On Twitter @sbhatt

Material from Seattle Times archives is included in this report.