Senior judges have agreed that dictating the use of ‘hot-tubbing’ for expert evidence would be a ‘step too far’ - but want more effort to encourage it.

The Civil Procedure Rule Committee urged caution over the extension of concurrent expert evidence but has asked to find types of cases where it should be the ‘default position’.

The practice was considered at a committee meeting in February – the minutes from which were published this month – where members heard that hot tubbing had not generally caught on, and was not widely taken up voluntarily.

A subcommittee set up to examine the issue reported the danger that hot tubbing would not be implemented until it is imposed through the rules or standard directions and the onus was on a party to opt out.

The group said the fundamental virtue of hot tubbing was the improved quality of expert evidence and improved efficiency in the trial process. The subcommittee stressed that it should be encouraged, subject to safeguards to protect the fairness of the trial, especially to the losing party.

It was found there was a danger that judge-led joint expert examination could ‘curtail’ cross-examination. 

The committee heard the evidence of one judge in a clinical negligence case where four cancer experts gave oral evidence and it was ‘impossible’ to hot-tub them. The judge continued: ‘When I raised the issue with the parties at the start of the trial, one counsel was very hostile and the other (quite junior) looked blank, as though he did not know what hot tubbing was. Concurrent expert evidence had not been considered by the parties and appeared alien to their culture and experience of litigation.’

The subcommittee said that without active promotion and a warning to the parties that it was likely to be imposed, hot-tubbing would make ‘little headway’ in personal injury and clinical negligence claims.

Lord Justice Briggs (pictured), chair of the CPRC, noted that until full docketing of cases was in place, work at the earlier stages of case management might be wasted. He also stated there may be a burden on the trial judge, which would be both a training and resource issue.

The subcommittee was told to identify specific types or classes of case where hot-tubbing may be appropriate and look at how it should be raised with the parties.

It was suggested hot-tubbing may be best suited to the Mercantile Court and Technology and Construction Court (now part of the Business and Property Court).