As Johnny says every paper will have a slant, otherwise it would just be copies of Reuters' output. No-one should ever believe everything that's written in any newspaper.
As I have said before on this thread (I appreciate you are new) there are articles in the Guardian pushing the economic case for Brexit and Matthew D'Ancona wrote a piece not that long ago praising IDS' work during his time in Welfare. Personally I consider both those arguments to be utter rot - especially the second one - but it's not fair to paint the Guardian as a paper which only publishes Islingtonista propaganda. It's a shit, inaccurate stereotype. If you don't like it then don't read it, but it's unfair to make it out as the Morning Star's sister publication.
Whereas the drivel that the Mail pumps out is almost entirely unworthy of any credence whatsoever, poorly written and outright false information most of the time, stuff that's not even hard to check. Without even getting into the racist and fascist undertones in much of their political output lately.