Some 500 baggage handlers and check-in staff at Stansted Airport could go on strike during one of the busiest weekends—the two-day bank holiday at the end of this week.
Talks aimed at preventing the strike are continuing between the Transport and General Workers Union (T&G) and GMB, as well as Swissport.
There is a pay dispute over an improved pay offer from airport ground-handling agents Swissport, as well as Sunday shift premiums and sickness notes.
The unions told BBC news that discussions held on Sunday as disappointing and frustrating.
Their members voted three-to-one in favour of industrial action to secure an improved pay offer.