Archbishop Angelo Amato clarified that this issue not only comes from biblical teaching but also from natural law.
"A Catholic cannot support legislation that, for example, introduces marriage between two persons of the same sex; it goes against biblical revelation and against the natural law itself," he told the Italian newspaper Avvenire.
Given the importance of the natural law, the prelate disclosed that his congregation is preparing a statement on the subject and that, with this objective in mind, "all Catholic universities worldwide have been consulted."
"The responses from all over the world are very encouraging, including from universities considered more 'difficult,'" Archbishop Amato explained. "The natural law is most important because, among other reasons, it might be the sole basis for fruitful interreligious dialogue.
"Many Catholic politicians ask for clarifications on this type of argument -- if later they wish to act or succeed in acting coherently, is another question.
"In any case Catholic politicians should always remember that they should never give their consent to the introduction of laws that go against moral principles. In cases where such laws are already in force, then they can limit themselves to try to attenuate their reach."