BRUSSELS — Ryanair cabin crew members from five European countries will go on strike on Sept. 28, threatening hundreds of flights, a Belgian union said on Thursday.

Staff from Belgium, the Netherlands, Italy, Spain and Portugal will stage a stoppage on the Irish no-frills airline, the CNE said, after several European labour unions met in Brussels.

"Unfortunately, discussions continue without results," CNE delegate Yves Lambot told AFP at the meeting, describing negotiations with Ryanair management.

Ryanair workers — pilots, ground staff and cabin crew — are demanding improved working conditions and want their contracts to be based on the law in their country of residence rather than Ireland.

"They have promised to change our contracts into national contracts by 2022. This is too late for us. We want 2019," Lambot said.

Shortly before the announcement in Brussels, Ryanair insisted that the strike would fail in its attempt to cause "travel chaos".

"The overwhelming majority of Ryanair's flights and services that day will operate as normal," the company's chief marketing officer Kenny Jacobs said in a statement.

The Sept. 28 strike will be the biggest strike in the company's history according to the unions.

It comes after a strike in five countries in August, which forced the cancellation of 400 flights in the middle of the holiday period, affecting 55,000 passengers.

On Wednesday, the company suffered a 24-hour cabin crew and pilot strike in Germany prompting the cancellation of 150 out of 400 flights.

A typically combative Ryanair CEO Michael O'Leary described it as a "failure".

"We are not easyJet, we will not roll over every time we are threatened with a strike," O'Leary told reporters in London, mocking a rival low-cost carrier.

A threatened pan-European strike by Ryanair staff on Sept. 28 will be "unsuccessful" in its attempt to cause "travel chaos", the Irish no-frills airline said Thursday.

Ryanair said in a statement that it rejects "false claims made by Belgian union CNE that strike action by its small minority of cabin crew on the 28th September would cause 'travel chaos'", as a meeting in Brussels Thursday was set to confirm the walkout involving staff also from Italy, the Netherlands, Portugal and Spain.

The carrier's statement came a day after dozens of flights were disrupted in a walkout by German pilots and cabin crew, the latest flare-up in a bitter Europe-wide battle for better pay and conditions.

"If there is a further unsuccessful cabin crew strike on the 28th September... then, as we demonstrated in Germany yesterday, Ryanair will pre-advise customers of a small number of flight cancellations, and the overwhelming majority of Ryanair's flights and services that day will operate as normal," the company's chief marketing officer Kenny Jacobs said in Thursday's statement.

He added that Ryanair would "carry the overwhelming majority of the 400,000 passengers who will be scheduled to fly with us that day". — AFP