More than 1,200 security guards, baggage handlers and wheelchair attendants across LaGuardia and JFK have given strike notice, according to an official announcement from SEIU 32BJ, the service workers union that has been helping them organize around the Fight for $15 since last winter.

This notice is precautionary, to make sure that the airlines have time to prepare for a potential disruption in airport security.

The workers are employed by Aviation Safeguards, a non-union subcontractor for Delta, British Airways, and United. (Note that while the announcement mentions cabin cleaners, we have confirmed that this group is not participating.)

According to the union, "The strike, led by security officers, is a response to repeated, illegal threats and intimidation these airport workers have endured while fighting for $15." Aviation Safeguards has allegedly illegally ordered employees to take off their union buttons, and threatened to fire them for striking.

Aviation Safeguard employees make the Port-Authority's mandated minimum wage of $10.10, without benefits.

As a whole, the airline industry relies heavily on non-union subcontractors. In January 2014, cabin cleaners, bag haulers, and other minimum wage airport employees—all employed by subcontractors—rallied outside of Port Authority, demanding a living wage, in addition to vacation days and health benefits. Later that month, 32 protestors were arrested outside of LaGuardia while rallying for similar benefits.

For comparison, employees at San Francisco International airport have had a $12.93 per hour minimum wage and 12 paid days off per year, plus health coverage—since 2001.

All 1,200 Aviation Safeguards employees will make an official vote on the proposed strike on Monday. If the vote is in favor, they will then determine the start date and terms, in time for an official announcement on Tuesday morning.