Actually, I think we can measure this more objectively.

At the last UK election, the readership of Sunday papers that advised their readers to vote Tory was 19M. The readership of the Daily papers that advised their readers to vote Tory was about the same. Now some people buy two newspapers on the same day, but to counter that, some people don't buy both Daily and Sunday papers. Overall, we can say that the media advised approx 19M different to vote Tory, compared to about 3M for Labour and 1M for the Lib Dems.

However, this media advice ratio of 19 : 3 : 1 compares to a UK Election voting ratio of 10.7 : 8.6 : 6.8. So we can safely say that the UK media is far to the right of the electorate, and that a viewpoint that which is neutral with respect to the electorate will look left-wing compared to most media.

What we can't say from this data is how more left wing the electorate would be if the media didn't attempt to pull the electorate to the right.

Now, being less objective, this bias really ought to have been obvious, since most of the UK media is owned by extreme far-right tax-dodging billionaires who are not representative of the ordinary electorate.

I got readership figures from: http://www.nrs.co.uk/toplinereadership.html

Eh? The Transfomers DVD went straight to movie without commercials? Fantastic!
Or perhaps that's because the entire movie is a product commercial. Perhaps you're the perfect consumer!