as i understand it, a civil partnership doesnt give quite the same legal rights as a marriage done in a registry office with regards to inheritance etc. i could be wrong but i think it was something about that.
in my opinion, anyone should be able to get married legally, ie in the eyes of the law not the church, and have teh same rights, wether its straight or gay people. there should be no difference.
however the church is a seperate issue, and one politics should stay out of. you cant make the church accept something it doesnt want too when it is governed by different rules.