Charles Kennedy has called on Europe to take the lead in setting global standards for tackling environmental pollution.

The Liberal Democrat leader also slammed the Bush administration for failing to take climate change seriously.

And the prime minister came under fire for failing to use his links with the American president to push for tougher action on pollution.

"When the Bush administration - representing a country with five per cent of the world's population but accounting for a quarter of all CO2 emissions - refuses to take seriously even the proposition of climate change, it is gambling with all our futures," Kennedy warned on Tuesday.

"If the prime minister's special relationship with Mr Bush is to mean anything, it must be used to bring the US into line on the environment.

"So today we are saying Britain should be standing shoulder to shoulder with Europe on the environment.

"It is time the European Union stepped into the vacuum that the US is leaving and leads the push to raise environmental standards world-wide."

Priority

Unveiling a new poster campaign on the environment in the final week of election campaigning, Kennedy said his party had "placed a high priority" on green issues.

"Tackling the environment begins at home," he added.

"It is Liberal Democrat councils up and down the land who put the environment at the heart of planning decisions, and come up with innovative solutions for waste management and recycling.

"In London, Simon Hughes is proposing a raft of policies for a cleaner, greener city - and to tackle the pollution that blights our Capital.

"But in the European elections, we can vote to join up with our European allies to make a real difference to the global environment."

The Lib Dem leader also warned that the planet is facing "an environmental disaster".

"In Britain, the Office for National Statistics has suggested that 2,000 extra people may have died last August because of the extreme hot weather," Kennedy said.

"Climate change is already a reality, not a far distant threat."