Their efforts are the most recent salvo in a debate that's likely to continue for months, regardless of what the commission rules. A denial would require Duke Energy to come up with an alternative plan to meet the state's growing energy needs, resulting in more hearings.

A go-ahead would advance the case to the next stage of public comment and opposition on environmental permits required to build the power plants. And any approval could be conditioned on Duke Energy adopting energy efficiency programs that would require separate public hearings to work out details.

Tuesday's plea to the commission was in response to a letter sent last week by 18 state lawmakers, urging the commission to put off the ruling for three months. They wanted the commission to weigh alternatives to building the state's first major power plant project in a quarter-century. By John Murawski