Mitie has today announced upcoming leadership changes at HMP Millsike, as the establishment moves into its next phase of its operation.
Current Director, Samantha Pariser, will move into a new strategic role within Mitie. Appointed to lead the establishment through its first year of operation, in a role designed to guide HMP Millsike from mobilisation into a fully functioning prison, she has provided the leadership needed during this crucial phase. During her tenure at HMP Millsike, Samantha has been instrumental in establishing a safe, and stable operational environment that now accommodates nearly 1,000 men.
The new Director, Sarah Mallender, will join HMP Millsike in June, bringing almost 30 years of experience in social justice, custodial and immigration removal settings. Sarah is currently the Centre Director at Heathrow Immigration Removal Centre (IRC), the largest IRC in Europe, having joined Mitie in 2022, and previously held senior roles in private prisons, HM Prison and Probation Service (HMPPS) and the third sector, in both the UK and Australia. Sarah will bring a proven ability to lead and develop professional, high‑performing teams with a sustained commitment to operational excellence in complex settings. In May 2025, the Home Office Honours Board nominated Sarah to attend Buckingham Palace in recognition of her services at Heathrow IRC.
In the meantime, Paul Newton will take on the role of Interim Director of HMP Millsike. Paul is a well-respected veteran of prison operations, with more than 35 years of experience across HMPPS, having served as Governing Governor at HMP Drake Hall, HMP Swaleside, HMP Birmingham and most recently at HMP Hewell. His extensive operational and national experience, including work to enhance services across the women’s prison estate, underpins his strong track record of driving safety, stability and performance.
Russell Trent, Managing Director, Mitie Care & Custody, said:
“Samantha has made an exceptional contribution during her tenure at HMP Millsike, helping guide the establishment from its construction phase into a safe, stable and fully functioning prison. She has laid strong foundations for the future, and we are delighted that she will continue to support Mitie in a new strategic role.
“As HMP Millsike continues to build up to full capacity, we remain committed to creating an environment that is focused on rehabilitation. Paul’s leadership will ensure continuity and momentum as we continue developing a purposeful, structured regime that equips men with the skills and qualifications they need to succeed on release. We look forward to welcoming Sarah in June. Her expertise in leading complex operational environments will ensure continued
Notes to editors
About HMP Millsike
HMP Millsike in Yorkshire is a 1,468 place Category C resettlement prison for men, which opened in March 2025 and is operated by Mitie Care & Custody. It is the first ‘green’ prison in the UK, running solely on electricity, and has been purpose-built with a clear focus on rehabilitation and reducing reoffending. Its model centres on education, skills development and purposeful industry, supported by initiatives that maintain family links, promote wellbeing and prepare people for successful resettlement. Millsike is committed to providing a modern, safe and supportive environment where individuals can build the skills and confidence needed for a positive future.
About Mitie: The Future of High Performing Places
Founded in 1987, Mitie employs 84,000 colleagues and is the leading technology-led Facilities Management, Transformation and Compliance company in the UK. We are a trusted partner to around 3,000 customers across the public and private sectors, working with them to transform their built estates, and the lived experience for their colleagues and customers, as well as providing data-driven insights to inform better decision-making.
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