The Connecticut Supreme Court is considering whether the state violated the law by not studying the environmental impact of a major natural gas expansion plan approved in 2013.

Critics claim the plan to expand natural gas service to 300,000 homes and businesses is increasing greenhouse gas emissions across Connecticut.

State regulators argue that the plan called for infrastructure upgrades that will actually reduce emissions.

If the court sides with critics, all expansion would have to stop until the state performs an environmental impact study.