The Guardian and the New York Times are also well known for political advocacy disguised as unbiased information, just towards the left rather than the right.
Sorry, I'll phrase it a bit more straightforwardly: if it came from Murdoch, it's much more likely to be a lie.
Because I live in WA, I used to read The Australian to get Australia-wide news and decent political analysis. I don't bother any more, it is absolute rubbish now and has been for a few years.
Or how about "I only believe left-wing news sources"? That would be more honest.
And just because you agree with a news source's bias, that doesn't make it true.