The South Bay Labor Council’s Executive Board — which represents nearly 100 local unions in Silicon Valley — voted Monday night to sanction a strike by members of Service Employees International Union (SEIU) Local 521, including more than 11,000 Santa Clara County employees.

“Today, the South Bay Labor Council on behalf of first responders, teachers, bus drivers, nurses and thousands of South Bay workers voted unanimously to grant Santa Clara County workers a strike sanction,” said Local 521’s Chief Elected Officer Riko Mendez.

Getting a sanction from the council is one of the last steps a local union takes before going on strike. Labor Council Executive Officer Ben Field said members of Local 521 demonstrated outside the Santa Clara Valley Labor Center Monday night — making their reluctant support for a strike known to the council.

“They would much prefer not to go out on strike,” Field said. “It is a last resort.”

Mendez made the case for his workers and County Executive Jeff Smith and his negotiating team spoke on behalf of the county at the council meeting Monday night.

“Our focus continues to be bargaining in good faith to reach an agreement that will ensure children, seniors and low-income families have the necessary services to be healthy and safe,” Mendez said in a statement. “We don’t want to strike, but we will to protect the critical services Santa Clara County families rely on.”

Field says after hearing both sides, the council’s board voted to sanction a strike without any dissent — adding that he hopes it doesn’t come to that.

“Hopefully the two sides will be back at the bargaining table and be able to negotiate a fair contract soon,” Field told San José Spotlight Monday night.

Workers voted overwhelmingly to strike in August, after months of negotiations over wages and other benefits, including health care and child care, with the county stalled. According to periodic updates published by the county’s Employee Services Agency, negotiators with the county have sweetened their proposed offer for raises twice since Aug. 7 — up from 12.5% over five years, to 14% on Aug. 26, and up again to 14.75% in its Sept. 9 report.

After workers voted to strike, Smith said his office was worried about the impact it would have on Santa Clara County residents.

“We will continue to meet in good faith at the bargaining table and we are open to discussing options that bring us closer to a contract that works for everyone,” Smith said in a statement.

The union says the county employees it represents have been working without a contract since June — and 97% of its members who cast ballots over two weeks in August voted to strike.

Contact Adam F. Hutton at [email protected] or follow @adamfhutton on Twitter.