yes i did read your link. it mentions changing rooms but not specifically the cubicles.
Law - Article 8 of the human rights act gives me the right of a private and family life. "It also includes your right to control who sees and touches your body. For example, this means that public authorities cannot do things like leave you undressed in a busy ward, or take a blood sample without your permission."
Although there is no specific law in regards to CCTV, it is regulated by Security Industry Authority. There was a FOI request for clarification on the law in regards to CCTV in toilets which i believe individual changing cubicles require the same level of privacy.
It states:-
2.1 Session 2: Legislation
Aim: To understand the different types of legislation and how they impact on Public Space Surveillance (CCTV) operations.
Objective 1: Identify how the Data Protection Act impacts on to the role of a CCTV Operator.
The meaning of “confidentiality” as it applies to the role of a CCTV operator:
compliance with 6 principles of the Data Protection Act
not disclosing information to any unauthorised persons relating to all operational aspects of the system and data security
no unauthorised recording e.g., using mobile phones or similar devices
no unauthorised copying of footage
body worn cameras
UAVs (drones)
Repercussions of breaches, for example:
dismissed, fines and potential prosecution
Objective 6: Identify how the offence of voyeurism impacts on public space surveillance (CCTV) operations
Safeguarding requirements:
safeguarding children and young people, and others including voyeurism, limits what you can view and record
what considerations to take before viewing CCTV material
voyeurism falls under the Sexual Offences Act 2003
[Reference: FOI 0351]
full article can be found here - www.gov.uk/government/publications/use-of-cctv-cameras-in-toilets/use-of-cctv-cameras-in-toilets