Give all 16-year-olds in the UK the vote
When a 16 year old is considered sufficiently mature to buy a beer, smokes, and pay for them by performing a blow job on screen, then we can indeed say that they’re old enough to aid us all in deciding which brand of thief will rule us. But a society that considers a 16 year old too immature to do those first three things is not one that can logically then turn around and state that they’re mature enough to do the fourth.
Damn, we currently insist that a 16 year old is too stupid to know whether or not to send someone a picture of their naked genitals. If the societal belief is that they’re that dim then what in buggery is the case for their being able to vote?