The government is falling behind on its commitments to switch a proportion of Britain’s car fleet to electric vehicles, an influential committee of MPs said on Thursday.

Take-up of electric vehicles has been slower than hoped in the UK, but the technology is essential to reducing greenhouse gas emissions from transport, and tackling the air pollution produced by the increased number of diesel cars on the road.

According to the guideline target recommended by the government’s climate advisors, ultra-low emission vehicles such as electric cars should make up 9% of the fleet by 2020, but current forecasts by the Department for Transport (DfT) show the figure by the end of the decade is likely to be about half that. Ministers have not said what should happen if the target is not met, nor produced a plan for beyond 2020.

Parliament’s environmental audit committee said ministers were failing to put forward the incentives and infrastructure needed to encourage drivers into electric cars, while air pollution was breaching regulations, with 38 of 43 clean air zones exceeding acceptable levels of nitrogen oxides.

In addition, the committee said the lessons of the Volkswagen emissions scandal, in which the manufacturer was found to have cheated on tests to make vehicles seem greener than they really were, had not been learned. Affected models were only starting to be withdrawn from the market, the MPs were told.

Mary Creagh, chairwoman of the committee, said: “The uptake of ultra-low emission vehicles is too low to meet the UK’s climate change targets at the lowest cost to the public. Air quality targets that were supposed to be met in 2010 won’t be hit until 2020 at the earliest. And it’s been almost a year since we discovered VW had fitted cars with cheat devices, but the government has still to decide what action to take against the company.”

Electric vehicles do not produce emissions at the point of use, and the UK’s electricity sector is becoming lower-carbon through the increased use of gas and renewable energy. They are one of the few options for removing carbon from transport.

Mike Hawes, chief executive of the Society of Motor Manufacturers and Traders (SMMT), which represents the industry in the UK, told the Guardian that manufacturers were investing billions of pounds in developing new electric and hybrid models, pointing to the rise in the range of makes available from five in 2011 to more than 30 at present. He urged ministers to provide more incentives to drivers.

He said: “We welcome the committee’s call for policy and fiscal certainty to drive the uptake of ULEVs [ultra-low emission vehicles], which will help the government meet its air quality and climate targets. Given this is still nascent technology which carries a price premium, the committee’s call for support across government, from the Treasury to DfT, to help stimulate market demand, is well made.”

Nissan, which manufactures the Leaf car, told the Guardian that sales were progressing well and that it expected further acceleration in future. An important advance, the company said, was that 98% of motorway service stations were now equipped with rapid chargers, a key consideration for drivers, and by 2020 it expected charging stations to outnumber fossil fuel filling stations.

Dale Vince, founder of Ecotricity, which runs the Electric Highway charging network, added: “We share the committee’s concern over the vagueness of the 2020 target for ULEVs - that target is a loose range, the mid-point of which is barely half what the Committee on Climate Change has said is required to keep us on track for our 2050 carbon targets. The government urgently needs to write our existing EU targets on renewable energy and air quality into UK law and set out clear policies for achieving them.”

The committee also called for a new target for two-thirds of cars and vans to be ultra-low emissions by 2030. Car manufacturers, including Nissan, would be given a greater incentive to manufacture such vehicles in the UK if clearer signals were evident in government policy, said Creagh.

Friends of the Earth said the government should go further still, to have a hope of halting the public health crisis from air pollution, which claims tens of thousands of lives a year and affects the quality of life of many more.

Jenny Bates, campaigner, said: “Road traffic [is] the biggest problem, and diesel the worst of all. [The government] must create a plan for phasing out diesel use on Britain’s roads, along with cutting traffic levels and preventing road-building adding to the problem. We know it can be done: the Netherlands and Norway are planning a ban on new diesel and petrol cars from 2025, which large parts of Copenhagen are traffic free.”

Air quality targets, set by the EU, were also at risk following Brexit, according to the report, entitled Sustainability in the Department for Transport. There has been no certainty yet from government as to whether these targets will be retained in UK law.

The committee also called on ministers to set out a clear plan for dealing with the aftermath of the VW emissions scandal, which could include bringing a prosecution against the company, and for the rail industry to clarify its steps towards reducing emissions, particularly from diesel locomotives.

Creagh said the government should redraw the priorities for the DfT to give greater weight to environmental issues. “Transport authorities throughout England have told us they have had problems with getting sustainable transport projects off the ground, because the DfT places more importance on economic benefits rather than the health benefits of improving air quality.”

The DfT said it was committing £600m over the current parliament to encouraging ultra low emission vehicles, for instance through grant schemes.

While the target of 9% of vehicles being low emissions by 2020 is endorsed by the Committee on Climate Change, a department spokesman pointed out that the government’s own aim is much lower, at between 3% and 7% of vehicles by the same date. The lower end of this target is forecast to be met.

“We see ultra-low emission vehicles as the future of road travel and we have set goals for almost all cars and vans on our roads to be zero-emission by 2050,” he said. “We are confident there will be significant further growth in the market.”

On the VW scandal, the spokesman said ministers took the matter “extremely seriously” and the department was calling for a Europe-wide investigation, for VW to resolve the issue for affected consumers, and for better tests that reflect real-world performance.

