Beware;
Just passed through Portsmouth (Sunday) on return from France, I have a BMW Carbon 7 Flip which clearly shows my face, was asked in a aggressive tone to remove my helmet. questioned why and was told again in a aggressive tone ... Quote "If you don't remove your Helmet you will be detained and denied entry to UK" I complied and muttered something like bloody jobsworth, they held my passport for a minute photographed it and told me I was to reported for abusing a Border Force Officer.
Big sign as you approach the passport office says please remove your helmet, they are just doing their job….