The fight over Broken Hill’s water supply continues.

The New South Wales Opposition is calling on the Government to release a business case for its plan to build a pipeline to supply the city.

The lakes that supply Broken Hill are running dry, so the Baird Government hads announced a $500 million plan to build more water security infrastructure.

“The Baird Government needs to release that business case, so the people of Broken Hill can judge this proposal on its merit and so everybody has the access to the same rights of information to be able to formulate alternative strategies,” Labor MLC Daniel Mookhey said.

Water Minister Niall Blair rejected the suggestion.

“If Labor had built anything in its term of Government, it would know it is not in the taxpayer's interest to release a commercially sensitive business case prior to procurement,” he said in a statement.