As Dzug states, Spain were prepared to accept UK passports that were up to a year out of date. However, I can find no reference to this concession still existing on the website of the Spanish consulate in London. I suspect that it may have been withdrawn when Spain introduced the requirement for travellers to register their passport details prior to travelling.
If you're travelling to Spain, it might be worth phoning the airline (who ought to know) to see whether the concession is still in place.
For all other EU countries, you're almost certain to be barred from travelling. Airlines face heavy financial penalties if they permit passengers to travel without the required documentation to enter their destination country. So your first hurdle would be getting past the airline's checks. If you managed to do so, it's still likely that you'd be turned back on arrival at the overseas airport.
You could try phoning the Passport Adviceline, as soon as possible. (It's available 24 hours a day): 0870 521 0410
However, unless your travel plans are for late on Tuesday (giving you time to get to a passport office prior to travelling) I think it's unlikely that you'll be able to travel.
Chris