Keir Starmer has vowed his party will “not let people pay a penny more” for their gas and electricity bills this winter, proposing to freeze the price cap at current levels and prevent the average household bill from reaching the £3,600. Senior sources said the party had limited time to get its message out before the next Tory leader, tipped to be Liz Truss, moves into No 10. The new prime minister will need to draw up a comprehensive cost-of-living package, despite Truss’ reticence to outline how it would help beyond tax cuts. Labor will increase efforts to promote its policy in the coming days, including with digital ads, campaign tools for local parties and direct mail for MPs to use. Plans for the summer offensive have been in the works since mid-July. In the coming weeks, the party will unveil more of its energy policy offering, including plans to upgrade 19 million homes to make them more energy efficient, double onshore and offshore wind capacity and triple solar power. Mr Starmer said Labour’s plan, funded in part by an expanded windfall tax, was the radical approach needed to help households and reduce inflation, comparing it to the inaction of a “lame duck” government. “We asked ourselves: do we want a plan that allows these prices to go up, causes this anxiety and then discounts some people after the event, but does nothing about inflation, or do we want to be more radical, bolder, more ambitious?’ he said on BBC Radio 4’s Today programme. “One of the benefits of our proposal is that it reduces inflation, which benefits everyone, but especially the most vulnerable and those who are less well off.” Sources close to Starmer say plans for the party’s conference will have to be adjusted based on what the new prime minister announces in his first weeks in office, especially if there is an early emergency budget. Paul Johnson of the Institute for Fiscal Studies, an economic think tank, has questioned whether Labour’s plan would help inflation much, saying the rate would rise again once the energy subsidy ends. Archie Bland and Nimo Omer take you to the top stories and what they mean, free every weekday morning Privacy Notice: Newsletters may contain information about charities, online advertising and content sponsored by external parties. For more information, see our Privacy Policy. We use Google reCaptcha to protect our website and Google’s Privacy Policy and Terms of Service apply. Starmer will visit marginal seats across the country almost every day of the next fortnight, while shadow chancellor Rachel Reeves will visit Scotland to outline how Labour’s plans compare with those of the SNP. “We are working on the assumption that Liz Truss will make a big offer on energy – we assume that what she is saying now is quite different to what she will do,” said a senior Labor source. “He will do what is politically important. So we have to make sure we look like we’re winning the argument now.” Senior Labor politicians will step up calls for Tory candidates to outline their plans more quickly. Ahead of Scotland’s first Conservative rallies in Perth on Tuesday night, Ed Miliband, the shadow climate change secretary, appealed to candidates to set out their cost of living packages ahead of the price cap announcement on 26 August. “If it was a banking crisis, the government would act. If it was a war, the government would act,” he said. “Tonight, in their recruitment, candidates must make it clear immediately whether they agree with Labour’s proposals. And if not, what are their alternative suggestions. The British people deserve answers, not more delay from a distracted and unknown Tory government.” Momentum, the left-wing grassroots group often at odds with Starmer, issued a statement backing Labor’s plan on Monday night, although it said it would have to be extended to full nationalisation. Hilary Schan, co-chair of Momentum, said: “Labour should be arguing for public ownership, at a fraction of the price. It’s the common-sense solution, supported by most voters, and the best way to keep raising bills.” Reeves told TalkTV on Monday night that she remained skeptical about full nationalisation, although she did not think the energy sector was “working today”. He added: “The whole point of the package we put together today is that every penny of it will go directly into reducing people’s bills.” Starmer faced criticism for the time it took Labor to set out its plan. A week ago, the Lib Dems said energy price rises must be stopped and former Labor prime minister Gordon Brown presented his own plan for the crisis. Starmer told BBC One’s Breakfast that his team had been working on the plan for more than six weeks. He added: “I’m not going to apologize for going on holiday with my children. It’s the first time we’ve had a real vacation in about three years.”