Travel in Spain, Greece, Portugal and the Canary Islands is expected to be affected by a general strike taking place on Wednesday, with a number of airlines cancelling flights.
The European Trade Union Confederation has called the general strike in response to concerns about employment and austerity in Europe.
The Foreign Office also updated its advice to warn travellers to expect significant disruption at Spanish airports and to be aware of public demonstrations in city centres that could affect public transport.
"Check for transport delays before arriving in Spain and allow extra time for journeys," it said.
The Foreign Office added that public services in Portugal are likely to be impacted.
"If you are travelling on that day (or on the days before or after November 14), you should keep in touch with your tour operator or airline," it said.
In a statement British Airways said: "A general strike is planned for Spain on Wednesday, 14th November 2012, which may disrupt transport throughout the country. We are therefore offering customers the opportunity to change their travel plans."
Iberia has so far cancelled more than 200 scheduled flights on Wednesday
Here at Wexas we are actively contacting all of our customers with affected bookings to discuss their options.