The Police Federation of England and Wales says the proposed Welsh travel ban by ministers is 'unenforceable'.
From 6pm on Friday 16 October, people living in Covid-19 hotspots in England, Northern Ireland and Scotland will be banned from coming into Wales for the time being.
First Minister Mark Drakeford said the Welsh Government would look to introduce the restrictions by Friday, should Boris Johnson not bring in his own measures to the same effect before that date.
Mark Bleasdale, Police Federation of England and Wales’ Welsh Lead, said: “On the face of it, this is unenforceable because of the difficulty of identifying where people are coming from and where they are going to.
“There will also be plenty of individuals travelling legitimately from areas which are not high risk, and this will only add to the other difficulties officers face when policing the existing regulations.
“Some areas of Wales are already in lockdown, and many individuals are already unable to travel in and out of counties unless they have good reason. In other locations provisions are more relaxed, so this proposed travel ban adds yet another level of complexity to policing.
“We would ask members of the public to continue to be supportive and realise this is an extremely challenging period for frontline officers.
“Policing in Wales is already over-stretched due to the pandemic and because crime rates have returned to pre-COVID-19 levels. However, my colleagues will continue to do their utmost to protect the public in their usual professional manner.”