A couple of weeks ago, @TheRealNooshu put together a petition to the UK Government, to make public websites available free of charge on mobile data. I've just been informed that the petition is now live and available to be signed: https://petition.parliament.uk/petitions/781594
If you're eligible to vote in the UK, do sign if you can; New Zealand have proved it can be done, and as Matt states in the petition text, nearly 4% of people in the UK can only get online from their phone, so they shouldn't be penalised for that when trying to access government services.