Pensioners will go cold and energy bills will stay high unless the next Tory prime minister makes insulating homes a “national mission” that could save people £11bn in three years, Ed Miliband has said. The shadow climate change secretary said Britain is facing a “cost of living emergency” partly caused by the Conservatives’ failure to insulate homes. He said both Liz Truss and Rishi Sunak bore responsibility for that failure, and urged them to reverse cuts to energy efficiency and insulation schemes. “Unless they change course and adopt Labour’s plan, pensioners will go cold, bills will stay high, and we will have to import more gas from Putin and his cronies,” he said. “If the Conservatives were serious about cutting energy bills, they could start right now, by delivering the Warm Homes Plan that Labour has called for. “A proper national mission would save 19 million families over £1,000 on their bills, as well as creating good construction jobs, and boosting our energy security.” Miliband said the government had done nothing on insulation since Keir Starmer called for an urgent plan to upgrade the 19m British homes that need energy efficiency improvements. Labour said its plan would save an average of £1,000 per home, meaning that if 1.9m homes were insulated a year, the savings in the first three years alone would be £11.4bn. Miliband said Sunak as chancellor had blocked efforts to spend billions on energy efficiency and Truss’s expected chancellor, Kwasi Kwarteng, oversaw the “botched” green homes grant scheme. Sunak said earlier in the Tory leadership campaign that he would prefer to refocus money on insulation rather than subsidising the installation of heat pumps or retrofitting public buildings. He said: “If we can refocus that money to do these types of interventions, which are quicker and cheaper, that seems like a sensible thing for us to be focusing on.”