Opposition parties have accused Rishi Sunak of “economic illiteracy” and a lack of seriousness over the climate emergency after he announced a plan for the UK to become energy independent while at the same time making it harder to use onshore wind. Before the fifth and final round of MPs’ voting for the Conservative party leadership on Wednesday, the former chancellor set out what he called an “energy sovereignty strategy”, intended to achieve UK energy independence by 2045 at the latest. But in the same announcement, Sunak pledged that as prime minister he would make it more difficult to build onshore windfarms in England. Ministers had been considering a relaxation of planning rules for onshore wind that were tightened under David Cameron’s government in 2014 following pressure from Tory activists who disliked wind turbines in rural areas. The view is shared by a number of Conservative MPs. The 2014 change required more local consultation and acted as a de facto halt on new developments in England. Planning rules vary across UK nations. The possible relaxation was potentially part of an energy independence plan, unveiled in April, which opted not to change the planning rules but did say the government would look at offering communities cheaper electricity bills in return for their consent for windfarms. But Wednesday’s announcement by Sunak’s campaign said: “In recognition of the distress and disruption that onshore windfarms can often cause, Rishi has also promised to scrap plans to relax the ban on onshore windfarms in England, providing certainty to rural communities.” Instead, he would put the 2045 self-sufficiency target into law and split up the Department for Business, Energy and Industrial Strategy, creating a new secretary of state for energy sovereignty. Offshore wind would be prioritised as well; this tends to be more expensive than onshore developments and takes longer to build. Sunak said: “Wind energy will be an important part of our strategy, but I want to reassure communities that as prime minister I would scrap plans to relax the ban on onshore wind in England, instead focusing on building more turbines offshore.” Ed Miliband, the shadow climate change secretary, said: “As Britain boils in an unprecedented heatwave, it is economic illiteracy and unilateral economic disarmament in the fight against the climate crisis that Rishi Sunak wants to keep the ban on onshore wind. “Anyone with such dangerous views is not a serious candidate for high office. But this is the reality: a Conservative leadership race in which candidates have engaged in fantasy climate denial that will lead to higher energy bills, damage our security and burdens future generations with extreme weather events.” Wera Hobhouse, the Liberal Democrat climate change and energy spokesperson, said: “Just a day after the UK’s hottest ever day, and with soaring energy bills, Rishi Sunak has shown that he is completely out of touch with reality. “Any supposed energy security strategy without onshore wind simply makes no sense. The plan flies in the face of any energy security plan and chooses to ignore climate change. This plan not only flies in the face of energy security but completely misunderstands climate change and its terrible impacts. “Onshore wind sites can be up and running, providing low-cost clean power for bill payers, in around a year. Not only is Rishi Sunak failing to grasp climate change but he is ruling out a key tool to bring down people’s energy bills as quickly as next year.” A source within Sunak’s campaign said offshore wind prices had fallen to record lows, and that in one recent auction it was less than that for onshore.