Hybrid cars that rely on traditional engines, such as the Toyota Prius, would be banned by 2040 under clean-air plans being drawn up by the UK government that would outlaw up to 98 percent of the vehicles currently on the road. Vehicles such as the Prius, the best-selling hybrid car in Britain, will no longer be classified as “environmentally friendly” enough to be sold, according to three people briefed on the government’s plans to tackle emissions and air quality. The exact wording is still a matter of consultation between several parts of the government, with the transport, environment and business departments all feeding into the final document, the people said. The plans are backed by Michael Gove, environment secretary, and Greg Clark, business secretary. But Chris Grayling, transport secretary, who has Toyota’s UK headquarters in his constituency, is resisting the limits. A spokesman for the Department for Transport said: “It is categorically untrue that government is planning to ban the sale of hybrid cars in the UK by 2040.