The actual wording is:
"Rest breaks 12. - (1) Where an adult worker's daily working time is more than six hours, he is entitled to a rest break.
(2) The details of the rest break to which an adult worker is entitled under paragraph (1), including its duration and the terms on which it is granted, shall be in accordance with any provisions for the purposes of this regulation which are contained in a collective agreement or a workforce agreement.
(3) Subject to the provisions of any applicable collective agreement or workforce agreement, the rest break provided for in paragraph (1) is an uninterrupted period of not less than 20 minutes, and the worker is entitled to spend it away from his workstation if he has one."
As you will see, there is no mention of when the break will be taken if it is not covered in a collective agreement or a workforce agreement and it is wrong to infer any conditions that are not specifically stated in the regulations.
As I said, there is no requirement for a break after a maximum of six hours, so that logic is not relevant.
Yes, they must have an uninterrupted break of at least 12 hours.
Colin Bignell