Ryanair pilots across the UK are set to go on strike later this month in a move that could cause major disruption to holidaymakers.
The British Airline Pilots Association (BALPA) has set strike dates following an industrial ballot that closed today.
Pilots are set to strike from midnight to midnight on 23 August and again on 4 September.
The union said 80 per cent of those balloted had voted in favour of strike action on a 72 per cent turnout.
A statement from BALPA said: "Decades of Ryanair refusing to deal with unions has resulted in two things.
"Firstly, a management that apparently doesn't understand how to work with unions and secondly a company that doesn't have a number of standard agreements that any union would reasonably expect in any workplace.
"That is why our claim includes many issues, including pensions, loss of licence insurance, maternity benefits, allowances and a fair, transport and consistent pay structure.
"We have made no progress with Ryanair management on any of those areas at all, seemingly because Ryanair management cannot understand how to go about working with us constructively, or how to negotiate. Ryanair has made no offer to Balpa in respect of its pilots."
Balpa's general secretary Brian Strutton said: "We have had no formal offer from Ryanair and it is imperative that we resolve this dispute urgently to avoid strike action. No pilot wants to spoil the public's travel plans, but at the moment it seems we have no choice."
Balpa members at British Airways have also voted to take industrial action in a separate dispute over pay.
Talks between the union and the airline will be held on Thursday under the chairmanship of the conciliation service Acas.
Ryanair announced last month that up to 900 jobs could be at risk amid a drop in earnings as the airline faces higher fuel costs.
The likely location of any job cuts is still to be confirmed.
A statement issued by Ryanair said: "We are disappointed that the pilots union BALPA is threatening to disrupt our customers travel plans during late August, early September, when it has the support of less than 30 per cent of Ryanair’s UK pilots.
"The independent result of BALPA’s ballot shows that less than 50 per cent of Ryanair’s UK pilots are members of BALPA, and of these, just 57 per cent voted in favour of industrial action.
"This is less than 30 per cent of Ryanair’s UK pilots.
"It is notable that over 70 per cent of Ryanair’s UK pilots are either not members of BALPA, or did not vote in BALPA’s ballot, or voted against industrial action.
"BALPA have no mandate to disrupt our customers holidays and flights, particularly at a time when UK pilots are facing job losses due to the Boeing MAX delivery delays, and the threat of a no deal Brexit on 31 October.
"Last year, Ryanair’s UK pilots agreed a 20 per cent salary increase, with senior captains earning up to £180,000 per annum, which is more than competitor airline pilots in Norwegian or Jet2.
"BALPA is recommending a pay freeze for Jet2 pilots in return for improved rosters (which Ryanair pilots already enjoy), and/or 12 months unpaid leave for Norwegian’s Gatwick pilots."
"This BALPA industrial action has no mandate from Ryanair pilots, is ill-timed just ten weeks before Brexit and will cause unnecessary disruption to customers holidays and travel plans.
"We have written to BALPA asking them to return to talks and we apologise sincerely to customers for any uncertainty that BALPA’s ballot may cause them."