The number of Massachusetts households receiving food assistance benefits is 26% higher than it was a year ago, and there could be another 700,000 people who are eligible for the aid but are not receiving it, advocates said Monday. Speakers at a virtual briefing hosted by the Massachusetts Law Reform Institute, Greater Boston Food Bank, Project Bread and Massachusetts chapter of the National Association of Social Workers highlighted a bill that aims to connect that population with nutrition benefits. Legislation filed by Rep. Jay Livingstone and Sen. Sal DiDomenico (HD 1500, SD 1015) proposes a common application portal through which Massachusetts residents would be able to simultaneously apply for MassHealth, the Supplemental Nutrition Assistance Program (SNAP), cash assistance benefits, veterans benefits, and subsidies for child care, housing and fuel assistance.