Staff at two major airlines have threatened to strike this summer, adding to fears of more travel disruption.
More than 97 per cent of Lufthansa pilots voted in favour of industrial action earlier this week after their union demanded a pay rise.
The German airline received overwhelming support for a strike, however negotiations are still underway.
A strike could have a significant impact given the airline services 10 UK airports including London City, Heathrow, Edinburgh, Glasgow, Newcastle, Manchester and Cardiff.
Marcel Gröls, a member of the pilots' union 'Vereinigung Cockpit' said the vote was an 'unmistakable' signal that Lufthansa had to take the needs of the cockpit staff seriously.
A Lufthansa spokesperson said strikes were not imminent and they had been working together to reach a compromise.
"Lufthansa is continuing to engage in constructive talks with the pilots union VC in order to find a joint solution for our pilots," they said.
"The next meeting dates have already been arranged with the VC."
Lufthansa has already faced significant disruption this summer. In June, 2000 flights were cancelled due to staff shortages. Last month, a walkout forced the airline to ground almost all flights from Munich and Frankfurt airports.
If staff do strike, they could be joined by flight attendants from Spanish airline Vueling, who have also threatened to walk out over issues regarding wages.
Cabin crew of the budget airline urged bosses to review wages and said they will walk out if their demands are not met.
This poses an issue, not only for the airline but holidaymakers heading to Spain this summer.
Strikes have already resulted in the British government updating their travel advice for those planning a trip to Spain.
"Possible strike action may cause some disruption to flights to and from Spain," states the Foreign Office website.
"You should consult your airline for updates prior to travel."