(CHAPEL HILL) -- The proposed merger of Charlotte-based Duke Energy and Raleigh-based Progress Energy is being challenged by clean energy advocates.  Several groups filed testimony late with the N.C. Utilities Commission late Thursday.

The Southern Environmental Law Center filed the testimony on behalf of Environmental Defense Fund, Sierra Club, the South Carolina Coastal Conservation League, and Southern Alliance for Clean Energy.  The groups contend that the merger would increase pollution from coal-fired power plants and make it more difficult for other clean energy innovators and service providers to enter the market. This conclusion comes from an independent analysis commissioned by the groups, according to a press release published by the Southern Environmental Law Center.

“The new Duke Energy faces a choice: the company can choose to be a leader in clean, renewable energy and efficiency, or rely on old technology and polluting fossil fuels,” said Gudrun Thompson, an attorney at the Southern Environmental Law Center. “We hope the new energy company will choose to move forward on clean energy to create jobs and save customers money while protecting the environment.”

In the testimony filed on Thursday, an expert in utility mergers and acquisitions outlines concerns about the proposal’s impacts on customers and the environment, and makes recommendations to the commission addressing those concerns.

Although the merger has been approved by the shareholders of both companies, the deal still faces approval by various regulatory agencies.  Top officials with both Duke and Progress hope to complete the merger by the end of this year.