I don't know for sure, but since Europe runs GSM towers it probably won't.
There is some CDMA service in or near Europe. Google for the CDMA industry association. So-called "Nordic Telephone" is CDMA in Norway, Ireland and Portugal. (Wrong frequency for a P+ phone.) Your P+ could work in Egypt, Ukraine and Russia.
Only Canada,Mexico,Bermuda,PR,USVI officially allowed outside the 50 US states at higher roaming charges. Might be possible to use the GSM side of an unlocked dual standard GSM/CDMA flip phone like a Samsung Renown or a Pantech Escapade..you would also need a local prepaid sim or a multi-country callback sim such as Tru,ekit simple calling,Telna,etc. Or a cheap GSM only unlocked phone on European frequencies with the appropriate sim would do the trick.