Check with the airline with which you intend to fly,some speciify a passport whilst others merely ask for photo id,in which case the new style photo driving licence would do
No airline that I know of will insist on a passport and only a passport. Ryanair, who are the most restrictive, insist on a passport OR a photocard driving licence. Others vary - some will accept a works ID for example.
Check with the airline you are flying with - it's the only relaible source.