Advantage Travel Partnership chief Julia Lo Bue-Said described the action called by the Unite union as "further disappointing news" to those looking to travel over the coming weeks during the school holidays.

"The airports are sure to be extremely busy throughput July and August," said Lo Bue-Said. "Without doubt, if these strikes go ahead, it will cause anxiety to travellers and potential disruption to their travel plans."

The 950 workers will strike for an initial four days from 28 July to 1 August, and then for a further four days from 4 August until 8 August. Affected airlines include British Airways, easyJet, Ryanair, Tui, Westjet and Wizz Air.

Lo Bue-Said did, however, offer a positive take, insisting the industry had built a "high level of resilience" into its operations over the summer months, albeit while urging airports and airlines to "do all they can" to ensure consumer confidence remains high and any disruption is kept to a minimum.

"We’re hopeful contingency measures will be put in place and the disruption to travel will be minimal," she added.

Rocio Concha, Which? director of policy and advocacy, said the strikes threaten more serious travel disruption and with the UK’s "weak" passenger rights protections, there is a risk of a repeat of last year’s "chaos".

"The government has recognised that an important step in putting an end to this cycle of nightmare travel experiences is for the aviation regulator to be given stronger powers," Concha added.

"The Prime Minister must now show he is on the side of passengers and prioritise giving the CAA the teeth it needs to hold airlines to account, by setting out legislation for new enforcement powers in the King’s Speech later this year."

A British Airways spokesperson said the action came as a surprise to its ground handling agent at Gatwick, GGS, after "constructive" talks this week. "It is continuing to work with the union to resolve this issue as a matter of urgency so as not to disrupt our customers’ travel plans," said BA.

EasyJet, meanwhile, which according to aviation analytics firm Cirium will be the airline hardest-hit by the walkouts, said it was "extremely disappointed" to hear of the proposed industrial action.

"More talks between our ground handler DHL and Unite are taking place early next week to try and resolve the issue and we urge them to reach an agreement as soon as possible," a spokesperson explained.

Also set to be impacted by the strikes is Wizz Air, which said it is in touch with the airport and its ground handling partner to limit disruptions for passengers. "In case of disruptions, we will reach out to any affected passengers who booked directly with the airline via email and SMS and let them know their options as soon as we have an update," a spokesperson assured.

A Gatwick spokesperson added: "We are aware of the recent ballot result. London Gatwick will support the airlines affected, who hold the contracts with the third-party ground handling and check-in companies, with their contingency plans to ensure that as many flights as possible operate as scheduled."