Police officers are being told to stop allowing people to sit on benches for 'long periods' of time.
New guidance on "What constitutes a reasonable excuse to leave the place where you live" has been issued to all policemen.
The papers reveal what is "likely to be reasonable" and what is "unlikely" in the eyes of the law - with people working 'from home' in parks being disencouraged.
The CPS originally released the practical guidance to comply with regulation 6 of The Health Protection Regulations 2020.
It says that driving for a long time to go for a short walk is unlikely to comply, nor does going for a short walk to a park bench, "when the person remains seated for a much longer period".
The guidance adds: "Exercise can come in many forms, including walks.
"Exercise must involve some movement, but it is acceptable for a person to stop for a break in exercise.
"However, a very short period of ‘exercise’ to excuse a long period of inactivity may mean that the person is not engaged in ‘exercise’ but in fact something else."
The guidelines for officers was issued by the National Police Chiefs' Council and the College of Policing last week.
It also reminds police officers that people who are able to work from home are unlikely to be allowed to "choose to work in a local park".
The regulations are also likely to allow people to go to work or volunteer, "but there is no requirement for the person to have any written proof.
"Police should not ask for ID documents or any other kind of document.
"There is no requirement for volunteers to work for a registered organisation or charity. There is no requirement for the volunteering to be related to covid-19."
However it does state that "moving to a friend’s address for several days to allow a ‘cooling-off’ following arguments at home" is likely to be allowed under the regulations.
It states the guidelines "allow people to move house".
"This means that individuals can move between households. But this should be a genuine move, for example measured in days, not hours."
