I'm a Tory.
The franchise model for water is an abomination, it is privatisation without marketisation which is what generates most benefits.
I would personally deny Thames Water the price hike and new loan such that it is allowed to collapse without outside investment.
I would then nationalise the scraps at pennies on the pound and restructure the water market like the energy market. Private supply and retail, National Grid Water i'd actually have 51% public.
I would however put everybody on a meter.