George Osborne's much vaunted stamp duty clampdown on properties worth more than �2m was unlikely to have any impact in Norfolk, a leading property expert said last night.

But there were fears that the chancellor's plan to tackle aggressive anti-avoidance measures, through a general anti-avoidance rule (GARR) could backfire on businesses and individuals legitimately aiming at tax efficiency.

Mr Osborne announced a stamp duty rate of 7pc on homes costing �2m from midnight, which will mostly affect buyers in London.

And he said that stamp duty on residential properties worth more than �2m which were bought via a company will increase immediately to 15pc, while the government will also consult on the introduction of a 'large annual charge' on such homes which have already been bought through companies.

And in a further clampdown, the chancellor said capital gains tax will also apply on homes bought through overseas companies, 'to ensure that wealthy non-residents are also caught by these changes'.

'I regard tax evasion and - indeed - aggressive tax avoidance - as morally repugnant,' Mr Osborne said. 'A major source of abuse, and one that rouses the anger of many of our citizens, is the way some people avoid the stamp duty that the rest of the population pays, including by using companies to buy expensive residential property.

'I have given plenty of warnings that this should stop. Now I'm taking action.

'If you buy a property in Britain that is used for residential purposes, then we will expect stamp duty to be paid. That is the clear intention of Parliament. I will not hesitate to move swiftly, without notice and retrospectively if inappropriate ways around these new rules are found. People have been warned.'

Guy Gowing, managing partner at Arnolds, said: 'The higher level of stamp duty on properties over �2m is unlikely to have much impact on the Norfolk residential property market. The most important thing the chancellor needed to do to encourage the nascent recovery was to ensure that the macro-economic measures he took create an environment of confidence, and especially continued low interest rates. He stated this as a specific aim, which is to be welcomed.'

Richard Tunnicliffe, CBI East of England Regional Director, said: 'We welcome the consultation on the proposed General Anti-Abuse Rule (GAAR). The legislation needs to balance the need to stamp out truly abusive avoidance schemes with the need for clarity and certainty around legitimate tax management.'

Clare Goodswen, partner at M+A Partners, said: 'It is essential that the provisions of the final legislation are reasonable and well constructed otherwise simple, well used tax planning measures such as tax efficient dividend planning or transferring assets into a spouse's name prior to disposal to utilize their capital gains tax exemptions will fall foul of the tax avoidance motive that the GAAR will contain.

'It should be written to counter-act contrived and artificial arrangements where the prime motivation is to avoid or reduce a tax liability, not simple tax planning measures which underpin taxpayers rights, enshrined in case law, to arrange their tax affairs in straightforward way that minimizes the tax that they pay.'