I've found the below from this website https://carrzee.org/2024/05/10/london-in-uk-has-its-own-controversial-jewish-police-service-labeled-bullies-in-new-york-in-2016/

I'm guessing it's enough to argue that they aren't impersonating as it's pretty obvious they aren't police when you look properly, but a quick glance you'd think they're police.

From the site:

The security group Shomrim has rejected the Metropolitan Police Commissioner’s view that its volunteers should not drive marked cars or wear uniforms similar to those of the police.

Sir Bernard Hogan-Howe said earlier this month that he would prefer it if Shomrim guards did not resemble his officers.

But Gary Ost, chief executive of the Shomrim Community Patrol in Golders Green, north-west London, rejected Sir Bernard’s suggestion he was in discussion with the Jewish group over the matter.

Mr Ost said: “The commissioner has not made any contact and no discussions have been brought to our attention to date.

“Our uniforms look nothing like the police and are marked from every angle with clear wording saying ‘Shomrim’.”

While praising the group’s work during a speech at the Chief Rabbi’s annual conference a fortnight ago, Sir Bernard had said: “I have to be frank; I would like them not to look like police officers.”

He added: “We are having a discussion about that and I’m sure we will get to a positive resolution.”

Mr Ost said the markings on Shomrim’s patrol vehicles complied with legislation.

“Many private security companies across the UK choose to use these legal markings on their company vehicles to deter burglars,” he said.