At least 1,357 flights have already been cancelled, diverted or delayed today, while some planes already on the way to Heathrow diverting to other nearby airports

Belfast City and City of Derry airports advised passengers due to fly to Heathrow not to travel to the airports and to contact their airlines. A number of flights to and from Heathrow are showing as cancelled on Belfast City Airport's website.

The positions — including airport ground workers and people who stock planes with food and beverages — are being eliminated because of overstaffing.

Southwest Airlines is cutting more than 100 jobs across four airports in the country, the airline said in a statement to KRON4. One of the four airports affected is San Jose Mineta International Airport.

Southwest Airlines is cutting employees at four major airports in California and Maryland, the latest belt-tightening in the carrier’s ongoing shakeup. The Dallas-based carrier will cut a combined 120 ground handling and provisioning frontline employees at four international hubs: Burbank,