Do you get a refund if they are on strike or is it a case of they'll give you another flight at a different date, which is no use for you as you've already booked your year holiday entitlement for this one flight/holiday, That's usually the case with these airline wankers 
They will try to fuck you over mate but make sure you make them aware of this:
You will get a full refund if your flight is cancelled for industrial
action
Due to EU regulations, airlines must provide you with an alternative flight to
your destination or a full refund to be paid within seven days of the
cancellation.
The only prob is they may not cancel it they may make you wait until another is available which in my experience can be anything from 1 day to a month, not good when you have to wait in the airport or risk losing your seat to someone there waiting already 
Airline companies are cocks, They dont refund you ticket prices even when you cancel your flight over 6 months from the date the flight is to take off, then they sell your flight for the same amount again. Why the fuck hasn't the government brought in new laws for this? I've lost around £8,000 just on flights over a decade as they dont pay refunds, They only give you the taxes back, but even when the original reiceipt show tax at lets say £400, they only give you £100 back. cunts