The Massachusetts Attorney General wants the state to bar third parties from supplying retail electricity to residential customers.

The recommendation was in reaction to a report by her office in late March that found such customers paid $176.8 million more for electricity during the period July 2015 through June 2017 than if they had remained with the local utility.

Nearly 500,000 customers in Massachusetts buy electricity from third-party suppliers. Of that number, 37% have low incomes.

More than 700 complaints have been lodged against competitive suppliers with the attorney general in last three years. The report found that low-income customers paid $231 more a year on average for electricity than if they had remained with the local utility. In some cases, the amounts were as high as $541.

New York has a moratorium in place against energy service companies signing up subsidized low-income customers until the companies consent to state supervised audits.