All new London black cabs will be electric by 2020 as part of London mayor Boris Johnson’s drive to improve London’s poor air quality – now considered to be one of the biggest public health issues facing the UK, with the capital being the worst offender.

The target of a universal fleet of emission-free black cabs within 10 years is outlined in the Conservative mayor’s final air quality strategy, published today. It comes as the government today separately announced details of 4,000 new charging points for electric cars across the UK.

With pressure to act to help reduce the worst air pollution in Europe, Johnson plans to get the dirtiest cabs off London’s roads by refusing to license any taxi over 15 years old from 2012 – a move which is expected to see 1,200 cabs scrapped from the fleet of about 22,000.

The decision to keep vehicles nearly 15 years old is in recognition of the cost involved. Licensed minicabs will face a stricter bar, with any vehicles of more than 10 years refused a license from 2012.

All new taxis entering the fleet by April 2012 will also have to meet the strictest emission vehicle standards, and eco driving training for those training to be black-cab drivers will be made mandatory from January the same year – in effect a “greener knowledge”.

To encourage London cabbies to switch to low-emission alternatives, the mayor will couple the publication of his strategy with the announcement of a £1m pot designed to offer a reduction in the purchase price for taxi drivers upgrading to low-emission vehicles, and encourage the taxi industry to develop an affordable, workable vehicle in time for the new target.

All new taxis entering the fleet by 2020 will have to be “affordable zero-emission taxi capable of zero-emission operation”, with a 60% improvement in fuel economy required by 2015 from a baseline of 2010.

The targeted action on London’s cab fleet is part of a wider set of measures outlined in the mayor’s third and final draft on how to clean up London’s air, which is the worst in the UK and among the worst in European cities.

Johnson is under pressure to produce a credible package of measures to tackle London’s poor air quality, which sees an estimated 4,267 Londoners dying prematurely each year because of long-term exposure to airborne pollution, according to figures released by city hall this year.

The government received a second and final written warning during the summer from Europe to clean up London’s air or be taken to the European court of justice and face fines of up to £300m for being in breach of air quality standards. It is currently waiting the outcome by the European commission of a time-extension request.

Johnson also intends to revoke one of the first decisions he made after taking power in 2008, by returning to twice yearly MOT tests, though these will be done “more simply and cost-effectively” at a local garage rather than via a few available inspection centers.

Johnson said: “London’s magnificent cabbies are famous the world over for their top-notch service, but I also want the capital’s taxi fleet to match up to the highest environmental standards that a great city like ours deserves.

“From 2012 when the world heads to London, we will remove the oldest, dirtiest cabs from our streets. But we are also offering a juicy carrot, with the establishment of a fund to help speed up the introduction of electric black cabs. This forms part of a robust package of long-term measures to progressively clean up London’s air.”

Last week, the mayor announced the creation of the UK’s only zero-emissions bus route with the use of eight hydrogen buses that emit only water vapor from their tailpipes.