Plug-in hybrid cars will be responsible for 10 per cent of Britain's carbon emissions by 2035, according to analysis conducted for The Telegraph, amid rising concern they are being wrongly touted as a green option for drivers. The Government has said hybrid cars, which use both battery and internal combustion engine technology, will continue to be sold for five years beyond the 2030 deadline for the phase-out of new petrol and diesel cars. But analysts say this will damage the country’s efforts to get to net zero Co2 emissions because PHEVs have been shown to emit up to four times as much in real-world scenarios than in official tests. Sales of PHEVs are expected to double in 2021, and grow to as much as 50 per cent of the market by the 2030s unless the Government imposes stringent criteria on sales, potentially posing a problem for the UK’s emissions targets. Analysis from NGO Transport and Environment for The Telegraph suggests that by 2035 emissions from 6.6 million PHEVs on the road could be as much as 20 million tonnes of Co2, around 10 per cent of all annual emissions as projected by the Government’s climate change advisers, the Climate Change Committee (CCC). By 2050, when the UK should be at net zero emissions, it calculates that PHEVs could contribute between 1.4 and 5.9MtCo2.