The U.K. government will extend and expand an incentive program for green cars that had been set to end in the coming year.

The plug-in car grant was introduced in 2011, and was originally scheduled to expire in early 2016.

But the program will now run until March 2018, with some modifications, according to The Guardian.

DON'T MISS: Electric Cars Could Slash UK Oil Imports 40 Percent In 15 Years: Study

The extension is backed by a £400 million ($595 million) funding package, and will benefit up to 100,000 U.K. car buyers, officials say.

That's twice the number of buyers who have received grants of up to £4,500 ($6,696) through the program since 2011.

As before, grants will be available to buyers of new zero-emission vehicles and plug-in hybrids, but officials reportedly now want to emphasize cars that have no emissions at all.

Vauxhall Ampera

Vauxhall Ampera

Vehicles with a zero-emission range of more than 70 miles--including both battery-electric and hydrogen fuel-cell cars--will be eligible for the largest grant.

In addition, plug-in hybrids will be eligible for a grant of £2,500 ($3,720), but there is now a £60,000 ($89,281) cap on purchase price.

ALSO SEE: U.K. To Miss Out On 200-Mile Chevy Bolt EV, GM's 'Electric Car For Everyone'?

Beginning in March, an additional £500 ($744) grant will be available to buyers who install home charging stations.

That should cover around half the average cost of an installation, officials say.

The government hopes to increase the number of zero-emission vehicles on U.K. roads as a way to combat poor air quality and climate change, although sales of such cars have only recently become energized.

2013 Renault Zoe electric car

2013 Renault Zoe electric car

Officials likely also hope the extension of the grant program will mollify environmental groups, which are largely unsatisfied with a recently-unveiled plan to reduce air pollution in major cities.

The plan calls for the creation of "clean air zones" in five cities, in addition to one already planned for London.

MORE: UK Official Says Encouraging Diesel Cars To Lower Carbon Was 'Wrong'

They'll require owners of the dirtiest trucks and buses to pay heavy fees to drive into city centers, but there is no such requirement for passenger cars.

London and certain other British cities have failed to meet European Union standards for nitrogen-oxide levels since 2010, but the government has delayed corrective action until now.

[hat tip: Lindsay Patten]

_______________________________________________

Follow GreenCarReports on Facebook and Twitter