More must be done to tackle the harmful emissions from construction equipment used to build facilities for the 2012 London Olympic Games, MPs have said.

A cross-party section of MPs and leading experts in transport pollution have signed an early day motion urging organisers to observe best practice.

They said the Olympic Delivery Authority (ODA) has not done enough to control dust and other emissions.

The ODA said it was committed to mitigating any effects of construction.

'Free to pollute'

Danny Stevens, from the Environmental Industries Commission, said: "The London Olympics has pledged to be the most environmental yet - that must include ensuring this huge construction project does not contribute to poor air quality.

"It is about time the ODA acted on its commitment to implement best practice, including protecting the public from poor air quality by ensuring that suitable pollution control technology is fitted to the equipment used on site."

"Cars, buses, lorries and other heavy-duty road vehicles have long been subject to strict emission controls, yet the equipment used on construction sites remains unregulated and free to pollute."

Campaigners said these efforts would reduce emissions by up to 87%.

The ODA said it would be monitoring pollution levels during construction work, including air quality checks and dust monitoring.

"We will also be reducing the number of vehicles on site by using rail and water where possible to transport construction materials, and will also be using ultra-low sulphur diesel for site vehicles," a spokesman said.