Ryanair's chief executive has issued a stark warning that 100,000 passengers could face flight disruptions next week due to an impending air traffic control union strike in France.

Michael O'Leary revealed to the Sky Money blog that the industrial action would set Ryanair back by approximately £20m.

Despite the company's ability to absorb the cost, he emphasised that it would ultimately be the customers who bear the brunt and urged them to voice their complaints.

Members of the SNCTA are set to strike from Tuesday 7 October until the morning of Friday 10 October over a dispute concerning pay and working conditions.

While the strike will undoubtedly impact flights heading to France, it will also affect those utilising French airspace to reach their final destination - these are referred to as overflights.

This includes flights to and from numerous locations including Spain, Italy and Greece.

O'Leary advocated for overflights to be shielded from strike action, arguing that disrupting them constitutes an abuse of the free single market.

On the first two days of the strikes, he disclosed that Ryanair anticipates being asked to cancel roughly 600 flights - with almost all of them being overflights.

"That's about 100,000 passengers who will have their flights cancelled needlessly next Wednesday and Thursday," he stated.

"On any given day at the moment, we operate about 3,500 flights and about 900 of those flights cross over French airspace and about two thirds of those, around 600 flights, are cancelled every day there's an air traffic control strike."

The Ryanair boss has criticised French air traffic control strikes for causing disruption to flights across Europe, despite the fact that the UK is not directly involved.

While he acknowledged the rights of French workers to strike, he suggested that Eurocontrol, a pan-European air traffic management organisation, could step in to manage the airspace and keep flights running.

"It wouldn't stop the French striking, they have the right to strike and we accept that but they should be cancelling local French fights, not flights from the UK to Spain or from Italy to Ireland. This is a fundamental breach of the single market," he stated.

He urged the government to "put pressure" on the EU Commission and the French government to safeguard overflights during industrial action.

"We bloody well demand that our overflights are protected. If British citizens today going to Italy, or we have Spanish visitors wanting to come to London, they should not have their flights disrupted or cancelled," he declared.

He accused: "They [the government] don't care about the travelling public and they won't get off their arses and demand that their overflights be protected."

A Department of Transport spokesperson said: "Airspace is sovereign, and it is for each state to decide how best to manage their own."

"We know strikes can cause disruption for passengers and airlines and airports have robust resilience plans in place to minimise their impact. "

Flight delays for six airlines with major UK operations are worse than before the coronavirus pandemic, new figures show.

Analysis by consumer group Which? found British Airways, easyJet, Jet2, Ryanair, Tui and Wizz Air were less punctual in the 12 months to the end of April than in 2019, before the virus crisis began.

Tui had the worst performance out of the airlines included in the research, which was based on Civil Aviation Authority data.

Just 59.2% of the carrier’s UK departures took off within 15 minutes of the schedule in 2024/25, down from 67.2% in 2019.

Airlines have blamed air traffic control (ATC) staff shortages and industrial action for causing much of the disruption to their flights.

European air traffic management body Eurocontrol has said the number of ATC officers in some parts of the network is 10-20% below what is needed to manage demand.

UK ATC provider Nats insists it is fully staffed.

Airlines are not required to pay out compensation for delays outside their control – such as ATC issues – and in some instances it can be difficult for passengers to find out the true cause of disruption.

Here is the percentage of UK departures within 15 minutes of the schedule for six airlines in 2024/25 and 2019:

– British Airways: 68.7% in 2024/25, 71.5% in 2019.

– Jet2: 68.0% in 2024/25, 81.8% in 2019.

– EasyJet: 67.8% in 2024/25, 70.6% in 2019.

– Ryanair: 66.5% in 2024/25, 77.8% in 2019.

– Wizz Air: 66.0% in 2024/25, 66.8% in 2019.

– Tui: 59.2% in 2024/25, 67.2% in 2019.