There is no health reason for it, we have litter laws but they still plan on doing it - yes, it's banning smoking in parks:
Bill Wearing, head of health and wellbeing at Cumbria Council, another authority considering a ban, said: ‘No one wants to see anyone smoking near children’s play areas. It is getting to a stage where people think it is socially unacceptable in parks.
‘Once it becomes socially unacceptable, it becomes a lot easier to bring in laws.’
So you see, dear reader, "denormalisation" is the prelude to prohibition.