Right and wrong at the same time
DISCLAIMER: I am writing from the US and my specific knowledge of UK finances is sorely lacking.
From that vantage, this seems like a straw man argument to me. It matters not a whit what the "share" is: what matters is facts on the ground. Here in the US, real wages for workers have not risen since the 70's, yet CEO pay (as of the turn of the century) had risen 535%. At the same time, the S&P 500 had risen 297%, corporate profits 116%, and worker pay 32.3% less inflation of 27.5%. While the minimum wage did rise in 2007, the disparity has only increased, and been exacerbated by offshoring and the economic debacle of recent years. Since many were tempted to use their homes as bank accounts (with the concomitant bubble) a huge number are now actually behind.
For comparison, from 1949—79, family income by quintile rose 116% for the bottom 20%, 100%, 111%, 114% and 99% for the top 20%, with the top 5% rising a 'mere' 86%. But from 1979—2001, the same figures are 3% for the bottom 20%, 11%, 17%, 26% and 53% for the top 20%, with the top 5% gaining 81%. (The source for this is the US Census Bureau).
Taxes, however, are currently at their lowest level since the Eisenhower administration. Despite the scapegoating of many on the right (with particular attention to Governors like Scott Walker of Wisconsin and their funders, like the Koch brothers) even the "generous" salaries and benefits of public sector workers pale — they can lead a decent lifestyle (and we can't have that, can we? If you are suffering, the right thing to do is pull down the person on the rung right above you. Pay no attention to the man behind the curtain.)
There is a group here (probably little known in the UK) callled ALEC (the American Legislative Exchange Council), though which the Koch brothers and their ilk write 'model laws' which have been passed word for word (excepting 'insert state name here') by many state legislatures. These are the source of the anti-union movement in this country — unions which had been declining for years anyway, not least because of their own shenanigans and abuse (I'm looking at you Teamsters).
I could go on for pages. (In fact, I have. I've written a book about these and other related matters, which you can find at http://www.lulu.com/product/hardcover/the-root-of-all-evil/6525037, should you be so inclined).