It would definitely need a lot of careful though to get the balance right. As it stands, the UK's maximum capital gains tax rate is 28% vs. 45% for the top rate of income tax.
This leads to the situation, not at all uncommon or illegal, where a lot of highly paid professionals are the directors of their own limited companies, take no salary, and get all of their remuneration in the form of dividends taxed a maximum rate of 28%.
For reference, anything over £31,786 per year is taxed at 40% -- before that it's 20% (national insurance is extra). It's usually the case that freelancers or contractors are able to invoice via their own limited companies, whereas employees are not normally able to do it this way and have to go the income tax route.
Doing this is entirely legal, and many people argue that it's perfectly 'fair', but it definitely doesn't look fair to those unable to take advantage of that setup who earn, say, £60,000.
Some figures, very rough and rounded to whole pounds:
Earning £60,000 and paying
income tax:
---------------------------
£10,800 - 0% = £10,800 Tax free allowance
£31,700 - 20% = £25,360 'Basic Rate' tax
£17,500 - 40% = £10,500 'Higher Rate' tax
===========================
£60,000 gross = £37,210 net
(before national insurance
contributions are taken)
Earning £60,000 and paying
capital gains tax:
---------------------------
£11,000 - 0% = £11,000 Tax free allowance
£49,000 - 28% = £35,280 Highest CGT rate
===========================
£60,000 gross = £46,280 net
(before national insurance
contributions are taken)
So under that setup, someone who can't use the limited company method is nearly £10,000 a year worse off before national insurance contributions are taken into account. Even assuming some costs for accounting, that still leaves the second person significantly better off.
(Edited to remove duplicated calculations at top of comment.)