Officially no, but you hardly ever have to do anything other than wave your passport at the authorities on either side of the channel. Go for it, what can they do to you?
Duh! If it's expired it's expired! Is it worth risking? YOu might get into France cos they don't check but what about coming back? I wouldn't bother...
I live in a ferry-port and go to France relatively often. In my experience, I have never got onto the boat without my passport having been looked at by the check-in-desk people...sometimes by the outbound Customs people, too, and - occasionally - by the French authorities on arrival. I should think your chances of getting away with an expired passport are remote, at least at my usual departure-point.
If you're flying you'll need a passport. If you're going any other way, you can generally drive through waving anything that looks vaguely like a passport at them!!