I'll admit it- it was not a good idea to start this having had little sleep due to teething screamy baby, but neither would 140 characters beat sufficiently erudite response to it either so here it goes:
So the perceived problem is that through the use of perfectly legal tax-efficient practices "Big Business" is able to squirrel away up to £80Bn in "lost" income from the state; the following assumptions can be made from this logic:
1. Presumably these Big Businesses are compressing down the £80Bn into rolls of fivers and firing them at passing seagulls off the channel.
2. That if only the state had this extra £80Bn the peoples republic of the UK would flourish, all needs met and growth in living standards obtained.
We can instantly debunk 1 whilst in turn showing 2 is also rubbish:
A1: That £80Bn, whether put into the hands of a few directors or that of the company shareholders is not wasted; at worst it is being put into consumer goods and services keeping yaught-builders, kitchen fitters and Michelin-star chefs in business; more likely this money is being reinvested by savvy, profit-hungry (ergo, those least likely to invest in something unlikely to return on their investment) people, providing new jobs whilst providing better and cheaper products.
A2: Considering that on recent historical evidence of the last Labour-ious government and the whopping great hole in finances they were paying today's public services with tomorrow's tax money (after all that is all that debt is: tomorrows bill) despite massively inflating the take of the public sector in the economy we are seeing the quality of life stagnating (at best).
So the assumptions are wrong, and that money is best staying in the hands of those who earnt it in the first place.
And even to ignore this issue and continue on to "collecting" this "lost" revenue: more tax-collectors? Increasing the complexity of the tax office would simply eat into the aforementioned extra funds, reducing what you can do with it at the end (an example being inheritance tax, which once the cost of collecting it is taken into account is early revenue neutral).
None of which takes into account the Laffer Curve; why bother earning that extra £80Bn if they are going to take it from you? Why not enjoy your high paid job salary and the extra time you would use to increase your profitability or, better yet, move your business to a better tax and regulatory environment?
Does noone think things through anymore?