LPT Request: How to politely tell someone that what they're asking you to do is not your job, It's actually their job?

I work for an organisation that is rife with political drama. You need to be careful how you say things if you don't want to be a part of this drama.

I also don't want to do other people's work for them because they feel like being lazy. How can I tell them to get stuffed without telling them to get stuffed?