Nearly 300,000 air passengers have had their plans ruined after 1,500 flights were cancelled over two days due to a crippling strike by French air traffic controllers.

EasyJet axed 274 flights across today and yesterday including 150 today; and Ryanair said 70,000 fliers were impacted after it cancelled 468 services over the two days.

British Airways was trying to use larger aircraft to try to mitigate disruption, while Air France and Lufthansa both had to reduce their flight schedule for the two days.

Some 40 per cent of flights at airports in Paris were cancelled today on the eve of the start of the European summer holidays, one of the year’s busiest travel periods.

The strike by two French unions, which is in protest against alleged understaffing and ‘toxic management’, has had a significant impact on flights across western Europe.

Families are being particularly affected today as they are forced to rearrange plans just as French schools close for the summer and many head on their holidays.

French civil aviation authority DGAC asked airlines to cancel 40 per cent of flights today at Charles de Gaulle, Orly and Beauvais airports serving Paris; a 50 per cent reduction at Nice; and 30 per cent of flights in Marseille, Lyon and some other cities.

Separately, Eurostar passengers also endured disruption this morning with services delayed due to ‘operational issues’ and busy scenes at London St Pancras station.

Passengers in Paris were also disrupted today due to a ‘technical problem’, ‘over-running maintenance work’ and ‘Gare du Nord station being very busy’ – following cancellations last night between the UK and France due to an ‘incident’ on the track.

Industry association Airlines for Europe said the strike was expected to affect nearly 300,000 people across today and yesterday after cancelling almost 1,500 flights.

The group’s managing director Ourania Georgoutsakou said: ‘This strike is intolerable. French air traffic control already delivers some of Europe’s worst delay figures.

‘Now the actions of a minority of French air traffic control workers will needlessly disrupt the holiday plans of thousands of people in France and across Europe.’

Airlines for Europe added that French air traffic control had proven to be one of the weakest links in Europe’s ATC network, posting some of the continent’s worst delay records so far this year.

The association said the strikes also caused ‘almost 500,000 minutes’ in delays in Europe yesterday on nearly 33,000 commercial flights. 

Yesterday, half of flights in Nice, France’s third-largest airport, and a quarter of flights at Paris Orly and Paris Charles de Gaulle, one of Europe’s busiest hubs, were cancelled.

DGAC said 933 flights departing from or arriving at French airports were cancelled yesterday, some 10 per cent of the total number of flights initially scheduled. 

The proportion of cancellations rose to 25 per cent at the main airports in Paris. 

But disruption worsened today, the eve of the school holidays, with the DGAC asking companies to cancel 40 per cent of flights to deal with the strike.

Despite the preventive cancellations, DGAC warned that ‘disruptions and long delays are to be expected at all French airports.’

French Prime Minister Francois Bayrou described the strike as ‘shocking’.

‘Choosing the day when everyone goes on holiday to go on strike at air traffic control is taking the French hostage,’ he told BFMTV.

Ryanair, Europe’s largest airline, initially said yesterday that it cancelled 170 flights across the two days, affecting 30,000 passengers.

But then later on yesterday, the carrier increased this figure to 468 flights, impacting 70,000 passengers.

Ryanair said the strikes were affecting flights to and from France, but also flights over the country to destinations such as the UK, Greece, Spain and Ireland.

Ryanair chief executive Michael O’Leary said: ‘Once again on Thursday and Friday of this week, over 400 Ryanair flights and more than 70,000 Ryanair passengers and their families will have their travel plans disrupted by a tiny number of French air traffic controllers, engaging in recreational strikes.

‘Over 350 of these are overflights, which could and should be protected by the EU Commission.

‘The bizarre justification for this week’s ATC strike is their objection to ‘short staffing’. Every year they find something new to strike about.’

He added that Ryanair recognised the workers’ right to strike, but pointed out Europe’s airlines have repeatedly called on the European Commission to protect overflights.

Mr O’Leary continued: ‘It is unacceptable, that flights which overfly France, and which could operate without disruption, are needlessly cancelled, simply because the European Commission won’t protect overflights, or defend the single market. This is unacceptable.’

He urged European Commission chief Ursula von der Leyen to take action to protect overflights – those that pass over a country or region without landing there – during national air traffic control strikes, adding: ‘If she won’t reform, then she should go.’

EasyJet said it had made 124 cancellations yesterday and 150 today across its European flight programme.

An easyJet spokesman told MailOnline: ‘The national strike action by French air traffic controllers today is impacting all airlines operating to and from French airports and using French airspace.

‘As required by the French authorities (DGAC) easyJet proactively cancelled some flights in advance and customers were contacted directly with options to transfer to another flight for free or a refund.

‘As this action could result in further disruption to airline’s flying programmes, we advise all customers travelling on July 3 or 4 to check the status of their flights on our Flight Tracker online for the most up to date information. While this is outside of our control, we will do all we can to minimise the impact of the strike action.

‘On behalf of our passengers we are extremely unhappy with the strike action, particularly given the current performance of French ATC which has been the leading cause of airspace delays in Europe this summer.

‘Long term solutions must be found for our customers and crew who suffer repeated disruption.’

And a British Airways spokesman said: ‘Like all airlines, due to industrial action by French air traffic control, we’ve had to make some adjustments to our schedule. 

‘This is outside of our control, and we’ve apologised to our customers for the disruption to their travel plans. Our teams are working to get our customers to their destinations as quickly as possible.’

MailOnline understands BA is using larger aircraft wherever it can to help accommodate customers from flights the airline has been forced to cancel. 

Air France said it had been ‘forced to adapt its flight schedule’ but its long-haul network was not affected.

Lufthansa also reduced its schedule for the two days, affecting some flights in and out of Nice, Paris, Marseille, Lyon and Montpellier airports.

At Paris airports, passengers stared at departure boards loaded with cancellations to assess their options.

‘I came here on holiday to celebrate my wife’s 40th birthday, but now I’m stuck at Charles de Gaulle Airport,’ said Julien Barthelemy, a passenger travelling to Marseille from New York, late last night.

‘I’m currently on the waiting list for three flights and am waiting for a spot on the next one to become available.’

Lara, 30, was scheduled to take a flight from Paris to Berlin with her partner to visit friends.

“The flight was scheduled for Thursday evening, but we were informed on Wednesday that it had been cancelled. We had been able to get another ticket for free, for Friday evening, but that was also cancelled,” she told AFP, adding they had to buy more expensive train tickets.

Others caught up in the disruption included Nadia Rivet, a 51-year-old bank employee, who said: ‘We’re trying to stay positive, there are worse things, but it’s annoying,’

Ms Rivet was planning to spend six days in the French capital but her flight from the southwestern city of Pau yesterday morning was cancelled.

‘Everyone has the right to strike, but it’s punitive. Air traffic controllers aren’t the worst off,’ she told AFP.

But other passengers tried to take the disruptions on the chin. 

Eric Nouen, a 60-year-old travelling to Montpellier from French Guiana, a region of France in South America, said he was not going to complain.

He added: ‘Right now, everyone could go on strike. Everyone has a reason right now.’

The strike involved 272 air traffic controllers from a workforce of around 1,000 staff on duty, the DGAC said.

Transport Minister Philippe Tabarot said carriers would lose ‘millions of euros’ as a result of the strike.

‘Constantly choosing dates that will cause the most inconvenience to passengers does not seem to be the right approach,’ he added.

Mr Tabarot also called the union demands – and their decision to strike just as French schools close for the summer – ‘unacceptable.’

UNSA-ICNA, the second biggest labour group in the sector, launched the action to demand better working conditions and more staff.

The union is protesting against ‘chronic understaffing’, the planned introduction of a clock-in system, outdated equipment and ‘toxic management practices that are incompatible with the requirements of calm and safety’.

UNSA-ICNA claimed in there are not enough employees to handle surging air travel and that inflation is eating away at their salaries.

There are also protests at new reform measures aiming to more tightly monitor their work, prompted by a near-collision at the Bordeaux airport.

A UNSA-ICNA spokesman said: ‘The DGAC is failing to modernise the tools that are essential to air traffic controllers, even though it continues to promise that all necessary resources are being made available.

‘The systems are on their last legs, and the (air traffic control) agency is constantly asking more of its staff to compensate for its difficulties.’

The DGAC did not immediately respond to a request for comment on the trade unions’ concerns.

Their complaints echo grievances expressed by air traffic controllers in the US over antiquated infrastructure, dramatic staffing shortfalls and failing technology.

UNSA-ICNA was joined by the third largest union, USAC-CGT, which said the DGAC had failed to comprehend the frustration felt by controllers.

But the main union, SNCTA, had no plans to join them.

Airports in the south were particularly hard hit yesterday, with 30 per cent of flights cancelled in cities including Lyon and Marseille.

Business aviation, particularly in Nice and Le Bourget near Paris, has also been significantly affected.

Travel experts said delayed passengers should check their insurance policy to see if it covers them for such events – although they are unlikely to be able to claim compensation from the airline.

Alvaro Iturmendi, Confused.com travel insurance expert, told MailOnline: ‘If you are due to fly in this region over the next couple days, the best thing to do is to keep up to date with your airline, as they’ll issue any announcements of delays or cancellations.

‘And even if your flight looks unaffected, it’s always best to still leave plenty of time to get to the airport in case of any delays or queues.

‘As these strikes are from airport staff, it’s unlikely you will be able to claim compensation for any delays or cancellations as a result. But if your travel insurance policy covers you for such events, then you may be able to reclaim any costs this way.

‘Check your travel insurance policy to see if it covers strike-related delays or cancellations, especially if the strikes were announced before you bought your ticket.’

Kara Gammell, personal finance expert at MoneySuperMarket, added: ‘Under EU law, you may be entitled to a refund for your flight from the airline, but you may also be able to reclaim other costs, such as accommodation, on your travel insurance.

‘If your flight is delayed your airline has an obligation to offer you food, drink and accommodation depending on the length of delay.

‘You would only be eligible for extra compensation if you are made aware of strikes less than 14 days before the flight, as strikes are classed as ‘extraordinary circumstances’ with them not being the airline’s responsibility – unless it is their own employees, i.e. pilots or airline staff.’

It comes after Ryanair said on Wednesday that it had been hit by the recent conflict in the Middle East, and it cancelled more than 800 flights last month.

It is among those to have cancelled and rerouted flights amid the conflict between Israel and Iran, as well as continued attacks in Gaza, which last week saw flights halted at Dubai airport in the United Arab Emirates (UAE).

Caught up in the flight chaos today? Please email: mark.duell@dailymail.co.uk