Last year, a Boston activist group’s report sparked outrage when it revealed that Stop & Shop was charging significantly more for certain grocery items at a store located in a low-income Boston neighborhood than it was for the same items at a store in a nearby, wealthier suburb.

At the end of last month, in a bid to ensure that “Massachusetts residents have fair access to reasonably priced groceries,” a group of the state’s congresspeople sent a letter to Stop & Shop demanding that the Quincy-based grocery store chain explain its pricing structure.

Stop & Shop plans to respond to the legislators’ letter, according to a statement it issued to MassLive. The grocery store chain does not consider a neighborhood’s socioeconomic makeup when setting prices, it said.