MaximumPete: Passengers stranded by the recent BA strikes may not be eligable for compensation of between 250 and 600 euros, in spite of EU regulations, as BA claims that the rules don't apply to extraordinary unforseen circumstances.
That is exactly what the EU regulation says.
Article 5 relates to care and (if appropriate) compensation for cancellations. Compensation is calculated by reference to Article 7. Article 5(3) contains the exception:-
An operating air carrier shall not be obliged to pay compensation in accordance with Article 7, if it can prove that the cancellation is caused by extraordinary circumstances which could not have been avoided even if all reasonable measures had been taken.
Preamble 14 would be taken into account in interpreting Article 5(3), and says:-
As under the Montreal Convention, obligations on operating air carriers should be limited or excluded in cases where an event has been caused by extraordinary circumstances which could not have been avoided even if all reasonable measures had been taken. Such circumstances may, in particular, occur in cases of political instability, meteorological conditions incompatible with the operation of the flight concerned, security risks, unexpected flight safety shortcomings and strikes that affect the operation of an operating air carrier.