The Court of Appeal has rejected an attempt to allow accountants to benefit from legal professional privilege (LPP) in a high-profile ruling.

The ruling handed down today (13 October) rejected the contention of insurance company Prudential that the advice of accountants in relation to tax law could be covered by LPP, which would protect it from being disclosed to third parties.

The judgment – the result of a tax dispute between Prudential and HM Revenue – also rejected arguments put forward in the High Court that there was a case for creating a level playing field between lawyers and accountants with regard to LPP.

In reaffirming the sole right of qualified lawyers to benefit from LPP, the appeal court concluded that only Parliament could enact a major overhaul of privilege. The ruling also noted that there had been a number of cases in which reforming LPP had been considered over the last 40 years adding that "Parliament's failure to change the law in this respect is not an accident".

The dispute led to the intervention on opposing sides by the Law Society and the Institute of Chartered Accountants for England and Wales, which instructed Simmons & Simmons and Blackstone Chambers' Charles Flint QC.

Herbert Smith acted for the Law Society, fielding a team under head of tax Heather Gething and litigation partner Julian Copeman, with Brick Court Chambers' silks Sir Sydney Kentridge and Tom Adam instructed as counsel.

Prudential instructed PricewaterhouseCoopers Legal head of litigation Agnes Quashie with Blackstone Chambers' Lord Pannick QC instructed as counsel.

Any move to have weakened the position of lawyers with regard to LPP would have been viewed as seriously eroding the position of the legal profession in comparison with other professional advisers.

Copeman commented: "This is an important decision as it both confirms the unique status of legal professional privilege and the necessity of keeping it within clear boundaries. It is well reasoned, robust and compelling."

The news comes one month after an attempt to extend privilege for in-house lawyers in Europe came to an end after a ruling from the European Court of Justice that company legal teams are not protected in competition cases.