To say Sky rarely scrutinize Tories is nonsense. Jeff Randall is one of the most forensic interviewers out there - up there with Paxman, in my book. Jon Craig and Glenn O'Glaza can barely disguise their glee at anti-Tory stories. Adam Boulton is a bit of a Tory but still goes very hard at Tory ministers.
"Questioning" isn't left-wing.
Although there is bias in the interviewing, especially from Andrew Marr, Anita Anand, and Kirsty Wark, John Humphries, Stephen Nolan, Victoria Derbyshire and many others - in general, the interviews aren't too bad.
What particularly gets my goat is the "reporting" more than the interviewing. The BBC don't just report, they interpret, they spin. Often, the spin is by omission. The BBC never ever reports on EU excess, for example. Whenever American news is reported, the BBC is giddy with glee in being anti-Republican.
The vox pops always seem curiously out of kilter with opinion polls too. Yesterday, on the housing benefit report, all three of the "public" asked didn't support the changes. Look at the opinion polls, and you will see that the housing benefit cuts are perhaps the coalition's most popular policy.