Airlines claim flights have escaped disruption caused by a strike by ground staff at Stansted.
Yesterday saw the first in a series of walkouts at the airport by 100 staff employed by Swissport over changes to scheduling and holiday allocation.
The Unite union called the industrial action after the breakdown of talks last Friday.
A further strike is set for the weekend from Saturday until Monday morning and four days over the Diamond Jubilee weekend from June 2 to June 6.
Swissport handles flights for Ryanair, Thomas Cook, Thomson, AtlasJet and BelleAir.
The union’s regional officer Paul Bouch said: “Our members shift tonnes of baggage every day, but with a typical shift ending at 12pm and workers back on the ramp at 4am the imposed changes will leave workers with little time to recover.
“Unite has remained committed to resolving this dispute and agreed to suspend strike action over Easter to give talks a chance.
“It’s a shame that Swissport hasn’t taken the concerns of its loyal workforce seriously. Strike action is always a measure of last resort, but our members have had enough.”
Ryanair pledged to continue running a full schedule of flights during the planned periods of disruption while easyJet said its services were unaffected and the airport stressed that it was operating as normal.
“Ryanair may not be able to accept checked-in baggage on some or all flights, however it will allow all passengers to use online check-in and travel with carry-on luggage only to ensure their travel plans are not disrupted,” the airline said.
A spokesman called on the union to remove the strike threats for this weekend so that passengers can be sure their travel plans will not be interrupted.
A Swissport spokesman confirmed that contingency plans were in place to enable the airport to run as normal and it expected no disruption to services.
“Passengers are therefore advised to check in as normal with hold baggage, which can be checked in for all flights. The action is being taken by the trade unions following the rejection of a revised roster proposal.”
An airport spokesman said: “Stansted airport will be open and plans to operate as normal at all times.
“Swissport serve the following airlines: Ryanair, Atlasjet, Thomson, Thomas Cook and Belleair. Other airlines such as easyJet, Air Berlin, Germanwings, Pegasus will be unaffected by any industrial action.
“As always, we recommend that passengers allow plenty of time for their journey to the airport and arrive at least two hours prior to departure.”