And Business Stream, the largest Scottish non-domestic supplier, is already eyeing up opportunities south of the Border.

Proposals announced by water minister Richard Benyon yesterday will allow businesses and public sector bodies to switch between providers. The draft Water Bill will also incentivise efficiency and recycling.

The Department for Environment, Food and Rural Affairs (Defra) hopes to implement the proposals by April 2017.

Mark Powles, chief executive of Business Stream, said: "The Scottish experience has shown competition, in the right market framework, can deliver demonstrable benefits to customers of all sizes.

"Defra has recommended a steering group of customers and market participants will help ensure an effective market is created, and from our experience in Scotland that's something we'd strongly support.

"However, while we are keen to see the market opening as soon as possible, we recognise that pragmatism and rigour are critical to ensure a fully-functioning market which is able to provide long-term benefits to customers."

Although the Bill aims to free up water firms to connect supplies to move water to where it is needed, Mr Benyon dismissed suggestions of piping water from Scotland to south-east England as too expensive.