ExSimGuy,
I'm not ignoring you request but have in fact only just revisited the forum - in essence bjcc has given the answer I was have given,and yes, I am a police officer.
Personally I would happily make the request for a breath test in private if requested, my point was/is, and its been made perfectly well already, that it is wise not give any indication of awkwardness that could look like refusal - this isn't meant to be officious at all, just highlight the legislation as it stands.