Wrightbus has secured an order for 20 hydrogen-powered buses in a £12m Transport for London investment programme.

The new double-decker buses will be the first of their kind in the world and will form part of an initiative to encourage other cities to take up the environmentally friendly technology in order to cut harmful emissions.

Hydrogen is often hailed as the future of motoring. It is the most abundant energy source in the universe, however, difficulties surround storing it safely and the lack of a refueling network. The only waste product it generates is water.

Wrigthbus already supplies the English capital its iconic Routemaster vehicle.

On announcing the deal, Transport for London (TFL) said the investment would create jobs in Northern Ireland and help it achieve its target of getting zero emissions across the public transport network. It will also invest in a refueling network.

Mayor of London Sadiq Khan said: "We all have a role to play in cleaning up London's toxic air and I've always said that TfL should lead from the front. Following the launch of the world-first Ultra Low Emission Zone last month I'm delighted that TfL has today signed a contract to bring 20 state-of-the-art, zero-emission hydrogen buses to London's streets. We are investing a record £85m in cleaning up our bus fleet, and I am proud that London now has the largest zero-emission bus fleet in Europe."

The project is receiving £5m in funding from European bodies and £1m from the Office of Low Emission Vehicles.

The buses are set to enter service in 2020 on routes to Wembley Stadium and through the West End of the city - where millions of tourists flock every year.

Belfast Telegraph