Ryanair crew members have threatened to join pilots in taking industrial action this summer.
Earlier this week, around 100 Ryanair pilots - based in Dublin - announced a walkout on July 12.
Last December, Ryanair boss Michael O’Leary lifted its policy of refusing to recognise trade unions, averting strikes over Christmas.
However, pilots, cabin crew and ground crew say the airline has not done enough to improve their terms.
In Ireland, Ryanair’s dispute with the Irish Air Line Pilots’ Association (IALPA) continues, with pilots due to be balloted over strike action next week.
Now, the International Transport Workers’ Federation, representing many Ryanair staff across its European bases, issued the airline a list of demands following a summit in Dublin this week.
These, the Guardian reports, include improving economic and safety conditions and rostering and workplace culture, reducing agency employment and giving staff the right to sick pay.
“If Ryanair fails to respond promptly and appropriately then it risks industrial action over the summer,” said the ITF, which also branded O’Leary’s climbdown “an empty promise”.
A Ryanair spokesman said: the airline was “already engaged in extensive negotiations with national cabin crew unions across Europe”.
“all of these [issues], and other issues, are being negotiated and we have already concluded agreements in the UK and Italy,” the spokesperson added.
In the UK specifically, the low-cost carrier came to an agreement with pilots union Balpa in January, representing its 600 UK-based pilots.
In June, Ryanair further agreed to recognise the Unite union as representative for its UK cabin crew.