Okay, so I'm not known for tact, smoothness, or in general saying the right thing at the right time.
However, even I know enough not to make gaffes like this very often:
"I am entitled to an amount for every night I spend in Canberra," he said.
"Where I stay, whether I stay in expensive accommodation, or in cheap accommodation, in my own apartment or an apartment belonging to my wife, in a hotel or a serviced flat is immaterial, you get the same amount and where you stay is of no concern to the Government."
This really isn't a good approach at all. There may be, and probably are, very good reasons why MT should be paid this benefit. Focusing on the fact that "I am entitled" really sends completely the wrong message though: it sends the message that "I don't care about the people whose money I'm spending, I care only about getting every cent I'm entitled to".
Instead, focus on the benefits that your electorate get from this arrangement. I can't think of any right now, because I never get paid $175/night to stay anywhere. I'm sure there are some though - and, Mr Turnbull, you have plenty of staff to think of these things for you.
You'll come off sounding less like the arrogant, self-absorbed prick that you are, and more like you may actually care, just a little bit, about the people you purport to server.