It's DBS now, I don't believe it's a requirement however there are umbrella organisations that act as agencies for adventure sport and children's activities leaders to obtain an enhanced DBS check.
I heard that about Tony too, and I believe it was mentioned in passing at some point that they do have DBS checks since they frequently work with children.
And this place specifically states that their staff hold DBS clearances.
http://www.airborne-airsoft.co.uk/young-guns-2/
As does this as well
https://lincolnshireairsoftclub.co.uk/aboutus.html
So I think it's safe to assume that it's common practice for airsoft site staff to hold those clearances - and I imagine it's likely a requirement for the site insurance policy too.
I wouldnt had thought so.
Airbourne have a young guns game day marketed at young people, therefore it makes sense they have DBS checks, and likely to be part of the insurance.
As for others, I doubt they need/have DBS checks as children and young people shouldnt be left unsupervised in a marshals care. Its not a game marketed for children and I would imagine due to some dubious wording and huge grey areas they can happily get by without.
As with everything it will only get questioned or become mandatory if it passes that some noncey marshal has a dodgy background or says/does something inappropriate and it makes it to the media where there is some outrage and airsoft policies hve to get tighter due to it etc...
Funny though as my daughter wants to play and the mrs is not happy about her running around woods with a bunch of older men!!