The Supreme Court has overturned the 'rule' that expert witnesses were protected from being sued by their clients as a result of alleged failings on their part when giving evidence or conducting expert witness-related work. Although the case related to a medical expert, it will apply to an expert giving an opinion in any specialist field, including valuation and other property-related work.

The 5-2 majority judgment in Jones v Kaney (30 March 2011) overturns a principle that has been in place for 400 years.

There will be a great deal of discussion in coming months and years about the decision and its implications for anyone who agrees to become an expert witness. In the meantime, view the Supreme Court's own summary.

The reality is that in most cases experts have endeavoured to conduct themselves properly and professionally and in a manner consistent with the duties imposed on them. However, those duties, including the requirements of the Civil Procedure Rules, are perceived to have become more onerous, and there is no doubt that, as the effect of Jones v Kaney becomes more widely appreciated, there will be some who decide no longer to accept expert witness instructions or adjust their terms of business and fees to reflect the greater exposure to litigation that they may be accepting.

The erosion of the protections available to those engaged in dispute resolution work started some years ago, notably with removal of the immunity in favour of advocates conducting their advocacy (Arthur JS Hall & Co v Simons - 2002) and saw experts being exposed to orders requiring them to pay the costs unnecessarily incurred by those engaged in litigation as a result of the actions or inactions of an expert (Phillips v Symes - 2004).