Billions of pounds' worth of water contracts will be awarded to utilities in the coming weeks ahead of the opening of the business supply market.

The first major framework contract is expected to be awarded by Crown Commercial Services on behalf of the UK’s public sector which is understood to be worth between £800m to £900m.

A steady stream of contract awards from high street retailers Marks & Spencer, Next, Sainsbury’s and Argos are expected to follow in the coming weeks.

The water companies understood to be in contention for the largest awards from multi-site companies include Anglian Water, Scotland’s Business Stream and new venture set up by Severn Trent and United Utilities.

Britain’s two largest water companies formed Water Plus venture last year by combining their existing non-domestic supply arms in a bid to corner the market before it opens for competition in April this year.

In Scotland, businesses have been able to choose their supplier for almost a decade but the market in England and Wales will move away from regional monopoly supply for the first time next month.