Belu, the social enterprise bottled water company which hands all of its profits to the charity Water Aid, has won a £100,000 contract to supply dining rooms, canteens and select committee meetings at the House of Commons and House of Lords.
The move could be seen as a further sign that the establishment is taking on the concept of social enterprise in a climate of anger about big businesses with dubious records on paying tax.
Belu, which already supplies restaurants including Jamie Oliver's Fifteen, also a social enterprise, will provide water to Parliament for two years, replacing Hampshire-based Hildon.
The decision to switch from Hildon was taken by the House of Commons Refreshment Department. Five years ago, the department was criticised for using bottled water at all because of environmental concerns.
Belu, which has produced bottled water since 2004, insists its production of water is carbon neutral, using 100 per cent recyclable glass, besides being ethically responsible. Mineral water is sourced from Shropshire, Montgomeryshire and Cambridgeshire. It has donated £355,766 in profits to Water Aid, a charity which provides clean drinking water to the developing world, since 2011.
The contract is a boost to Social Enterprise UK's Buy Social campaign, which is encouraging consumers and businesses to choose ethical companies that are either not-for-profit or use their profits for environmental or community benefits. Earlier this year Parliament passed the Public Services (Social Value) Act to encourage the public sector to award contracts for all services to social enterprises.
Chris White, the Conservative MP who was behind the Act, said: "We need to ensure that ethics and sustainability are the heart of our economy, and I hope that Belu's success will get more people interested in the role social enterprise can play in achieving this."