By Eddie O'Gorman BBC News

Wrightbus has won an order for 10 buses

The hydrogen-powered buses should be on the streets of the city by 2010 in time for the Olympic Games.

Wrightbus is working with the ISE Corporation of California to deliver the new buses in which hydrogen is used to power an electric drive system.

The makers say the new bus offers a "sustainable, safe and clean power source", ideally suited for a densely populated city.

"As there is no carbon in the fuel, hydrogen-powered vehicles produce no carbon monoxide, carbon dioxide or particulate emissions," said Wrightbus business development director Jonathan Poynton.

"By the time of the London Olympics in 2012, Mayor of London Ken Livingstone wants to have hundreds of these hybrid vehicles on the roads.

"His aim is that eventually all the buses bought for use in the capital will be hybrid."

Mr Poynton said that as the price of fuel continued to rise, Wrightbus was getting inquiries from all over the world.

The company is in the process of producing 50 hybrid street cars for Las Vegas with the first deliveries due in the new year.