(CNN) — London's Heathrow Airport is facing "major disruption" as 350 ground handlers are set to begin a three-day strike over pay on Friday, the Unite union said Thursday.
The 350 union members, who Unite said were employed by aviation firm Menzies, will begin a 72-hour strike at 4.00 a.m. local time on November 18, according to a press release.
The press release said the strike at Britain's busiest airport would "lead to disruption, delays and cancellation for flights leaving Heathrow Terminals 2, 3 and 4."
It added that American Airlines, Air Canada, Lufthansa, Qantas, Swiss Air, TAP Air Portugal, Austrian Airlines, Egyptair, Aer Lingus and Finnair would be among the airlines particularly affected by the action.
Air traffic at Heathrow was plagued with disruptions over the summer as travel demand rebounded from pandemic lows.
In July, Heathrow put a daily cap on passengers for the remainder of the summer -- and extended it through October -- to deal with staff shortages and the surge in demand.
Year-to-date, the airport has reached about 74% of 2019 passenger levels.