THE UK ­Government has missed an opportunity by applying the same rate of corporation tax to companies of all sizes, according to one of Scotland's leading economists.

Chancellor George Osborne announced in this week's Budget that the tax would be cut to 21% in the next two weeks, and further reduced to 20% next year.

But he has missed a trick by failing to lower it further for the small and medium-sized firms that dominate the Scottish economy, a conference in Glasgow heard this week.

At a Budget Briefing hosted by the Sunday Herald, economics professor David Bell, from the University of Stirling, said: "That would have been more welcome than just freezing the duty on whisky.

"I have seen some work on corporation tax and the proposal in the [Scottish Government] White Paper [on independence] that it goes down by 3% relative to the UK rate, and there was an opportunity, you are absolutely right."

He added: "One of the things I have picked up recently is that as far as businesses are concerned, corporation tax is not their main concern.

"Out of all the taxes that they face, business rates are a big problem and the taxes they have to pay for employees, National Insurance in particular."

Concern was raised at the conference, sponsored by Skypark, McLure Naismith and Campbell Dallas, that new moves to tackle aggressive tax avoidance will hit individuals who genuinely try to manage their tax affairs as efficiently and legitimately as possible.

A further crackdown on avoidance was announced at the Budget, with anyone who has signed up to a disclosed tax-avoidance scheme now having to pay taxes up front.

The Chancellor said those who feel they have been unfairly treated can go to court to retrieve their cash, with interest. He said the measure would apply to schemes covered by its General Anti-Abuse Rule (GAAR).

Robin Shannan, chairman of law firm McClure Naismith noted: "The problem with HMRC is, will they go too far and start getting in the road of nice, normal people just trying to organise their tax affairs?"

Fraser Campbell of Campbell Dallas, added: "The difficult is to do with this thing called the GAAR, which people may not have heard of.

"The GAAR is untried at the moment, but basically the Revenue has the ability to say: 'We don't think that smells right.' You are then no longer at the innocent until proven guilty stage. It's pay now, get it back later if you win.

"It has turned the onus of the tax and legal system when it comes to fairly routine tax planning."