SEPTA’s largest union, Transport Workers Union Local 234, could vote to pull its 5,000 employees out of buses, subways and trolleys as early as Monday morning, Oct. 27.

The union published in its newsletter that, “the day of reckoning is fast approaching,” and it would hold a strike authorization vote Sunday, Oct. 26. Workers aren’t happy with what the authority brought to the table. SEPTA proposed to a five-year freeze on pension benefits, a 6 percent cap on wage increases for the next five years, and increases to health care costs, including upping contributions to health insurance premiums to 10 percent.

“Nobody likes to go on strike,” the union wrote. “But there comes a time when we have to stand up for ourselves and our families.”

SEPTA said that it will continue to negotiate a settlement.

Earlier this year, a one-day regional rail strike prompted President Obama to issue an executive order that established an emergency board to arbitrate between SEPTA and a union of engineers.