Spanish airline Iberia has cancelled over 400 flights due to a four-day strike by its ground service workers that is set to begin Friday on the eve of Epiphany, a major holiday in the country. The flight cancellations, which also affect the airline’s low-cost carrier Iberia Express and its regional airline Air Nostrum, will impact more than 45,000 passengers, Iberia said in a statement after talks with Spain’s UGT and CCOO unions ended late on Wednesday without an agreement. Iberia’s corporate director Juan Cierco said the strike would cause “very significant” disruption to thousands of travellers, warning that even if it was called off at the last minute, it would be impossible to reschedule the flights. Christmas gifts are traditionally given in Spain on January 6, the day of Epiphany when Christians recall the visit of the three kings to the baby Jesus, with colourful parades held across the country the night before. Many Spaniards travel to be with their families for the holiday, which is also known as Three Kings’ Day. Iberia’s ground service workers, which include baggage handlers, are protesting over the contracts signed by state-controlled airport operator Aena with new providers. The new providers have vowed to maintain Iberia staff but unions fear their working conditions will worsen.