Tony Blair's Labour government made a mistake in promoting diesel cars as they are now "killing people", former science minister Lord Drayson has said.

In 2001, the then Chancellor Gordon Brown introduced lower vehicle tax for diesel cars, on the grounds that they were less polluting.

That tax break remains in place today.

Lord Drayson, whose own business invests in clean energy, now wants the current government to act to change driver behaviour again.

"We have a much better understanding than we did just a few years ago of the health effects of the products of diesel, and they are literally killing people.

"It is is clear that in retrospect that it was the wrong policy ... we have got to take action really quite quickly," he said.

His comments come in the wake of the Volkswagen emissions scandal in which the German car maker was found to have rigged tests to make its diesel vehicles appear to emit less pollution.

About 11 million vehicles worldwide are affected, of which almost 1.2 million were in the UK.

Scrappage schemes

Lord Drayson - who has raced electric cars - served in several ministerial roles between 2005 and 2010 and was the science minister from 2008 to 2010 in Gordon Brown's government.

He said: "I think we should have things like a car scrappage scheme where people who want to trade in their diesel get an electrical car or hybrid. I think that's something the government should support.

The peer also called for more rigorous independent testing of emissions and diesel exclusion zones in cities.

"The car industry has got to accelerate the development of electric vehicles and we are going to see the need for a greater adoption of hybrids," Lord Drayson said.

The former minister's views will further alarm drivers of diesel cars, many of whom bought them believing they were less damaging to the environment.

Media playback is unsupported on your device Media caption VW scandal: What UK drivers need to know

The City of London Corporation - the local authority for the capital's financial district - called for urgent action on cutting diesel emissions.

Wendy Mead, chairman of the Corporation's environment committee, said: "Diesel was sold as an environmental solution but it is in fact an invisible killer. There are a range of proposals for reform of the UK's air quality strategy, but we urgently need to move further and faster on reducing pollution from diesel vehicles."

She added: "We urge the Government to consider wider actions that can be taken to reduce emissions from diesel vehicles in the short term."

Defending diesel

Government officials and business leaders are attending the National Air Quality conference in Birmingham on Thursday.

Mike Hawkes, Society of Motor Manufacturers and Traders chief executive, told delegates it was wrong to penalise all diesel engines.

"The latest diesel vehicles are the cleanest ever, with particulate emissions all but eliminated by filters and sophisticated after-treatment systems effectively reducing nitrogen oxide levels by 92% compared to earlier generations," he said.

"Given that diesel cars emit 15-20% less carbon dioxide (CO2) than a petrol equivalent, they also make a significant contribution to climate change targets - an environmental challenge which cannot be ignored in this debate."

Richard Folkson, president of the Institution of Mechanical Engineers, said there should not be a rush to scrap diesel cars given their contribution to reducing carbon emissions.

"If all new fossil fuel cars were to be solely petrol tomorrow for example, our average carbon emissions would increase by 16%," he said.

"What we need is a rapid introduction of a new testing regime that much more accurately reflects driver behaviour. Diesel has many attractive characteristics ... this is not the time to restrict our choices by casting it aside."