Whitty, who is the only Lord to have served on the boards of both regulators Ofwat and the Environment Agency, said the Bill “only tinkers at the edges” and that Labour would “vigorously query its main elements”.
According to Whitty, the government published “a very good” Water White Paper in 2011, but the Bill as it stands now was “much thinner in content”.
Despite this, Labour confirmed it would not oppose the main elements of the Bill.
While welcoming the introduction of non-domestic retail competition, Whitty questioned how transformational it would be and warned that it could put domestic customers at a disadvantage.
“We have to consider carefully the effect on household consumers. Twenty million household consumers will continue to rely on regulation rather than competition to get them a better deal. We will have to strengthen protections in the Bill to ensure that domestic consumers are not disadvantaged by the fact that part of the non-domestic market is getting a better deal,” he said.
In addition, Whitty also criticised the lack of a clause to allow water companies to exit the retail market and described the resilience duty placed on Ofwat as “a bit vague”.
However, Conservative Lord Crickhowell, former chief of the National Rivers Authority, argued that the water industry had welcomed the new duty and said “he was green with envy” that the regulators in the future were unlikely to face the same difficulties that had confronted him in his former role.
Whitty also said he was concerned that the Bill lacked passages on restructuring the financial structure of the industry and abstraction reform.
Line by line scrutiny of the Bill, during the committee stage, is scheduled for February 4.