The Respondents plead guilty to terrorism offences. On 13 November 2020, Colton J sentenced the Respondents to custodial terms of imprisonment. All sentences were to be served half in custody and half on licence. On 29 April 2021, the Counter Terrorism and Sentencing Act 2021 (the "2021 Act") received Royal Assent. Section 30 of the 2021 Act introduced Article 20A ('Article 20A') into the Criminal Justice (Northern Ireland) Order 2008 (the "2008 Order"). Article 20A provided that no prisoner convicted of certain terrorism offences shall be released on licence unless they have served two-thirds of their sentence in custody. The effect of Article 20A was that the Respondents must serve two-thirds of their sentences in custody and one-third on licence, rather than half in custody and half on licence. However, the end date of the Respondents' determinate custodial sentences was unaltered.
The Respondents appealed to the Court of Appeal. They submitted that Section 30 of the 2021 Act was incompatible with Articles 5, 6, and/or 7 of the ECHR. They sought an order that the terms of their original sentences be restored. The Court of Appeal granted a declaration of incompatibility to the effect that Section 30 of the 2021 Act is incompatible with Article 7 of the ECHR. The Court of Appeal found that Article 6 of the ECHR was not engaged and did not make a determination regarding Article 5 of the ECHR.
The Appellant was granted permission to appeal the declaration of incompatibility with Article 7 of the ECHR and the Respondents were given permission to cross-appeal in relation to compatibility with Article 5 of the ECHR only.

On 13 October 2010, Mr Pearce was sentenced to imprisonment for public protection with a minimum term of 3½ years (less time spent on remand) after he pleaded guilty to three separate offences of sexual assault committed in 2009. Mr Pearce has been eligible for release at the direction of the Parole Board since 2013, but he remains in prison. His imprisonment has been reviewed on four occasions. Most recently, the Parole Board in May 2019 refused to direct Mr Pearce's release but recommended his transfer to open prison conditions (the Decision). In accordance with the Guidance, the Parole Board took into account unproven allegations about other alleged sexual assaults by Mr Pearce against women and girls when assessing the risk to the public arising from Mr Pearce's release.
Mr Pearce challenged the Decision by way of judicial review. The High Court dismissed Mr Pearce's claim and held that the Decision and the Guidance were lawful. On appeal, the Court of Appeal held that the Guidance contained unlawful misstatements of the law regarding the use of unproved allegations in the assessment of risk. However, the Decision itself was held to have been proper and justified. The Parole Board now appeals to the Supreme Court, arguing that the Court of Appeal was wrong to hold that parts of the Guidance were unlawful.