Question to the Ministry of Justice:

To ask His Majesty's Government what assessment they have made of the effectiveness of polygraph tests, as administered under the provisions in the Counter-Terrorism and Sentencing Act 2021.

Prior to mandatory polygraph testing of high-risk sexual offenders on licence being rolled out across the Probation Service in 2014, an evaluation of its effectiveness with such sex offenders was published in 2012. The report is publicly available here: The evaluation of the mandatory polygraph pilot (publishing.service.gov.uk).

The Counter Terrorism and Sentencing Act 2021 introduced polygraph testing for terrorist offenders and came into force in June 2021. As of 12 July 2023, 92 polygraph tests have been administered by polygraph examiners working within the Probation Service National Security Division.

The Government committed to undertake a review of its use with terrorist offenders after a two-year period and report on its findings. The report will be a process evaluation focusing on specific points raised in the House of Lords including the numbers of terrorist offenders subject to testing, how results of polygraph testing have been used, the effect of testing on monitoring of licence conditions, and how frequently terrorist offenders are recalled to prison on the basis of polygraph test results. An impact evaluation is not feasible due to the low volume of eligible cases within this timeframe. The report is scheduled to be laid before Parliament in Autumn 2023.