Dale Vince, the green energy entrepreneur behind Ecotricity and prominent Labour backer, has launched a scathing attack on Ed Miliband.He declared that the Energy Secretary is responsible for making Net Zero “politically toxic”.The businessman, who has donated £5million to the party, branded Mr Miliband unsuitable for the role of Chancellor and accused him of putting ideology ahead of sound economics.Mr Vince questioned whether the Energy Secretary even had a basic understanding of value for money.He cited spending decisions made by the Department for Energy Security and Net Zero (DESNZ) as evidence of poor economic judgement.”It’s about economic competence,” he told The Telegraph.”It’s about having an understanding of even the basic notion of value for money.”I question whether he has that when you look at spending decisions like carbon capture and storage.”Mr Vince took particular aim at Labour’s commitment to spend tens of billions of pounds on heat pump subsidies and carbon capture technology, describing the investments as a “terrible waste of money”.Labour donor Dale Vince attacks Ed Miliband over Net Zero and warns against Chancellor promotion | GETTYHe argued that carbon capture technology remains largely unproven at scale worldwide and questioned whether the spending represented good value for taxpayers.”It’s madly uneconomic, so this makes me question whether he’s putting ideology in front of the economy,” Mr Vince said.”We need something else from a chancellor and someone who is more business-like.”He urged Andy Burnham, who is widely expected to succeed Sir Keir Starmer as Prime Minister later this month, to remove Mr Miliband from Government rather than promote him to the Treasury.Andy Burnham’s victory in the Makerfield by-election could see him as the next Prime Minister | GETTYMr Vince also expressed hope that the former Manchester mayor could reverse what he described as the damage done to public perceptions of green energy policies.The intervention adds to the pressure on Mr Burnham over speculation that Mr Miliband could become Chancellor following changes at the top of Government.Unite, which represents more than 1.1 million workers, has warned that appointing Mr Miliband to the Treasury would place a “noose” around job creation.Business figures have also voiced concerns about potential tax rises and the impact on economic growth.Mr Vince said he felt compelled to speak out after John Healey resigned as Defence Secretary over concerns about military funding.The Cabinet dispute centred on spending reductions, with reports suggesting Mr Miliband opposed cuts to his department’s budget to help fund defence spending.”Mr Healey resigned for want of a few billion pounds, which fatally undermined Sir Keir’s standing,” Mr Vince said.He also criticised the DESNZ, claiming it was holding £50billion while refusing to surrender any funding despite pressure on public finances.Mr Vince said this was “wrong and not in the national interest”.The Ecotricity founder suggested Wes Streeting, the former Health Secretary, would be a more suitable candidate to become Chancellor.He also indicated he intends to contact Mr Burnham in the coming weeks, but said he was uncertain whether he would continue providing financial support to Labour if Mr Miliband were appointed Chancellor.Before becoming one of Labour’s largest donors, Mr Vince had supported the Green Party and met Zack Polanski two months ago.A spokesman for the Energy Department defended the Government’s approach, saying, “Net Zero is the economic opportunity of the 21st century.”The spokesman pointed to projects including carbon capture in Teesside, the development of Sizewell C in Suffolk, and Scottish offshore wind schemes as examples of green investment that supports jobs, strengthens energy security, and drives economic growth.