Michael O’Leary has predicted that Rachel Reeves will make a hash of the autumn Budget and be ejected from 11 Downing Street by Christmas.

The Ryanair chief executive said Ms Reeves had shown herself to be unfit in the role of Chancellor, painting herself into a corner on taxation while caving in to pay demands from Labour’s union backers.

In a coruscating attack, he described her as a “deadbeat” who “doesn’t get business and certainly doesn’t get growth”.

Mr O’Leary said Labour had no chance of remaining in office unless Ms Reeves prioritised measures to kickstart the economy and jettisoned a promise not to raise taxes on working people.

He said: “Reeves will get fired or fall on her sword in the next 12 months. She’ll make a balls of the Budget and I don’t think she’ll still be there at Christmas.

“They’ll have a new chancellor with a three-and-a-half-year run into the next election who can move away from these unsustainable commitments that they won’t raise taxes.”

He predicted that Labour would “start moving on raising income tax, corporation tax and maybe VAT, but start cutting taxes surgically where they can”.

The Ryanair chief added: “I don’t think they have any appetite for real cuts, but it doesn’t matter what their core membership thinks.

“They’re not going to get re-elected if they don’t deliver growth.”

The comments are the latest sign that much of the private sector has become intensely disillusioned with Labour. Many executives supported Ms Reeves and Sir Keir Starmer ahead of last year’s election after the pair promised to prioritise growth.

However, last year’s record-breaking tax raid and the introduction of new red tape in the jobs market has led support to steadily ebb away.

Alpesh Paleja, the deputy chief economist at the Confederation of British Industry (CBI), last week urged the Government to commit to no new tax increases in the autumn and called for a “rethink” on Labour’s workers’ rights reforms.

Mr O’Leary spoke after revealing that Ryanair would add only one new aircraft at Stansted, its biggest hub, this winter. He said the slow pace of expansion was the result of Ms Reeves’s move to increase the air passenger duty (APD) departure tax.

The Ryanair chief wrote to the Chancellor urging her to trial a removal of APD at regional airports, while committing to lifting UK passenger numbers from 60 million a year to 80 million over five years were it to be dropped.

Instead, Europe’s biggest airline is “pivoting capacity away from the UK” and directing growth at markets such as Italy, Sweden and Hungary after Ms Reeves ignored his plea.

Mr O’Leary set out his winter plans against the background of a Photoshopped image of Ms Reeves wearing a dunce’s hat.

He dismissed the Chancellor’s argument that her woes stemmed from a “black hole” in the Government’s finances inherited from the Conservatives.

The Irish executive said: “The black hole wouldn’t be quite so big if the first two initiatives of the Labour Government had not been to pay off the junior doctors and the train drivers.

“I don’t think Labour has much credibility. I don’t think there is a lot of brain power at the top of the party.”

Mr O’Leary, who was a KPMG tax consultant before moving into aviation, was equally critical of the French government, which is on the verge of collapse amid a row over spending.

He said: “The French have always been unable to control their budgets. It’s time for them to sort out their mismanagement of the public sector.

“The idea that you can go to work at 28 and retire at 42 while somebody else pays for your nice high quality of life is mythical.”

One of the Chancellor’s key growth initiatives has been airport expansion, with Ms Reeves overriding opposition from those on the Left of the party, including Ed Miliband, the Energy Secretary.

However, Mr O’Leary was critical of Ms Reeves’s “faffing around over a third runway at Heathrow, which won’t be delivered this side of 2040”.

Describing the expansion plans as “mad and insane”, he said he does not expect to see a new runway and “nor should there be if it involves tunnelling under the M25”.

The Ryanair chief also predicted that mandates for the increased use of sustainable aviation fuel (SAF) across Europe would ultimately be dropped, as would the goal of achieving net zero emissions by 2050.

Government targets state that 10pc of airline fuel in the UK must be SAF by 2030, while in Europe the equivalent target is 6pc.

Mr O’Leary said: “The momentum of the whole green agenda has gone. Once Putin invaded Ukraine, it was in trouble. It’s the concern of middle-class people in Europe pulling wool out of their navels.

“The Americans have no time for it, nor do the Russians, the Chinese or the Indians.

“It’s more than a slippage – it’s going backwards. People are looking for more competitive solutions to their daily lives. The world needs growth more than it needs to be worrying about the environment.”

Oil majors such as BP and Shell “are all abandoning SAF production”, he added, with the green fuel stuff “gradually dying a death, which is what it deserves to do”.

SAF is a greener alternative to jet fuel made from waste oils and other bio products that can be farmed, absorbing carbon dioxide from the atmosphere as they grow.

While SAF is produced mostly from recycled cooking oil, Mr O’Leary said that swathes of farmland would need to be devoted to producing the fuel were it to ever satisfy the needs of aviation.

He said: “I’ve always been uncomfortable with the idea that we will promote people to grow food that we convert into aviation fuel instead of feeding people. I think when it starts to increase food prices there will be issues.”

He added that while Ryanair accepted the need to decarbonise, there was “not a hope in hell” of reaching the SAF targets as they stand.

Mr O’Leary was cheered by what he called the “significant retreat” of draconian environmental policies in countries such as Sweden.

Earlier this summer, the country dropped a levy of 76-517 krona (£5.50-£37.40) per passenger per flight, an eco measure introduced by the centre-Left government in 2018.

Mr O’Leary has led Ryanair for 31 years and will be 67 at the end of his contract as chief executive in 2028.

He said he would be “reasonably happy” to open a conversation with the board about extending his contract beyond that date, as he has “no desire to retire or spend more time at home with teenage children”.

At the end of his term, the Irishman will be due a bonus worth €160m (£138m) at Ryanair’s current stock price, though he said he is not counting his chickens just yet.

He said: “I haven’t been paid yet and this is a very volatile business. Let’s see what the price is like. I suspect by 2028 some other infamy will have been visited on our industry.

“It’s only four years since we had a worldwide pandemic, which I confidently predicted was a mild flu and would all be over in three months.”

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