I don't have a strong understanding from the philosophical side, but when I did the quick lookup of Plan B and Europe, I read a few statements from religious groups, which seemed to be, "IUD OK", but "Plan B not OK".
There are 2 basic types of IUD. One is copper, the other is plastic and impregnated (heh) with birth control hormones.
The latter is generally as acceptable to pro-lifers as regular oral birth control. Basically it allows for the same hormones to be used to prevent ovulation but at much lower dose because it’s more targeted.
The former, the copper one, is what pro-lifers tend to object to because while it is somewhat effective at keeping sperm from finding the egg it’s not THAT good at that, and it has a secondary effect of preventing successful implantation of a fertilized egg.
Re: dogmush’s point, I’m not sure how banning a couple specific birth control methods will go over. It’ll probably be a state by state thing. But in general I’d agree that attacking birth control now is poor timing at best.