As an example, we are responsible for our franking privileges. We are liable and responsible for whatever it is we're mailing out to our constituents or in any other role that we have as an MP. Whether we're a government MP or an opposition MP, I don't think it matters; we're all parliamentarians and we're all treated equally under the system.
Let's say, as an example, I said to a group who wanted to do a mass mailing, “Here are five boxes, and here are 2,000 or 3,000 franked envelopes with my name on it.” Then let's say I gave it to a third party, perhaps to my own political party, and said to them, “You can use these envelopes and you can mail out whatever you want under those envelopes, because I'm a member of the team and I want to be a good member of the team.”
If I were to do that, hand over those envelopes to a third party, my political party, my research group, and say, “You mail out whatever you want in my franked envelopes”, am I not still responsible for whatever is sent in those franked envelopes?