Some 150 ServisAir workers at Liverpool’s John Lennon Airport are on all-out strike.
The action by members of the GMB union was sparked by a row over compulsory redundancies. It affects flights by Ryanair, KLM, Wizzair, Flybe and Thomson.
The company is forcing 51 staff to reapply for 27 jobs.
Fire service workers at the airport could now be balloted after the GMB union claimed Peel Airports, the airport’s owner, had broken an agreement governing the strike.
The GMB union said that prior to the strike there had been an agreement that so long as other companies involved in the management of the airport or services did not become involved, then other branches of the union would not get involved.
Eddie Parker, GMB regional organiser, said workers employed by Peel Airports had been involved in escorting what the union branded as “scab labour” on to the site.
He said the union intended to inform Peel Airports that GMB members of the fire service had requested to be allowed to consult on the possibility of balloting for strike action.
He said the union would accept nothing but the withdrawal of all 24 compulsory redundancies.
Baggage handlers in the Unite union at Manchester Airport have voted for an overtime ban and a strict work-to-rule on Saturday, Sunday and Bank Holiday Monday.
And a full walk-out by aircraft refuellers will run from 5am on Monday until Tuesday lunchtime.
Staff at Gatwick and Stansted airports are now expected join the strike.
The move is in protest at Sevisair’s refusal to stick to a agreed 2.75 percent wage rise.