So, what exactly would you suggest? Forcibly disband the party because it disagrees with the morality of the current ruling party (however well founded those moral beleifs are)? What if it was a party that, for example, was founded on the principals of legalizing euthanasia, gay marriage and abortion? Would it be just as bad? Would you want them shut down? Or what about a party formed in 1940s Germany with the main focus being against the slaughter of Jews? Should they be shut down because they beleive a policy of the current government is morally misguided?
The basic idea of representative democracy is that people with strong enough opinions form parties and allow the populace of a nation to vote based on the parties whos ideals most closely match their own. All you can say here is that the people who join the party are paedophiles. If they won, then you could make more generalist comments.
I'm not defending the party, or the viewpoint. But as long as they're not doing anything criminal (which they may well be), all they're doing is expressing their opinions, and they shouldn't be prevented from doing that.