A lawyer representing communities in the Amazon devastated by an oil spill warned Parliament yesterday that a setback in their compensation fight could spark other environmental disasters.

Juan Pablo Saenz said a ruling by a US judge last week to deny affected people over $9 billion (£5.4bn) in compensation from Chevron would send a dangerous signal.

It was the latest twist in a decades-long struggle sparked by the dumping of billions of gallons of toxic waste into the Amazon by Chevron between 1964 and 1990.

Mr Saenz said: "If we lose this, if we can't collect this compensation, it won't just be us that loses. It will send a signal to other companies that they can abuse the environment."

He was speaking at a Friends of Ecuador meeting to win international backing for his bid to oveturn the US decision and win legal fights in Canada, Brazil and Argentina.

Labour MP Chris Williamson pledged to step up the cross-party solidarity campaign he has been leading in the Commons.

Thirty-two MPs from eight separate parties have signed a motion calling on Chevron to cough up the cash.

Mr Williamson told the Star: "It really is a David and Goliath struggle here and it's vitally important that parliamentarians like myself in the UK and in other countries get behind the little guy, because they deserve justice.

"If you compare the scale of the polution in Ecuador to what we saw in the BP oil spill in the Gulf of Mexico, it's something like 80 times greater."