Friends of the Earth have praised the Liberal Democrats for being "head and shoulders" above the other major parties on environmental issues.

The group's campaigns organiser, Tony Juniper, told a fringe meeting, "Towards a Greener Manifesto", that only the Lib Dems had linked the environment to all its manifesto policies.

And Lib Dem environment spokesman Tom Brake promised that the party would continue to give top priority to environmental concerns.

"We will make sure the environment underlines everything we are doing rather than it just being an add-on.

"We will have by far the greenest manifesto of all the political parties," he pledged.

He also outlined some radical ambitions for the next decade including reductions in road traffic and the eventual replacement of the internal combustion engine.

And he blasted the government for failing to live up to its own manifesto commitments and doing nothing to help industries attempting to develop alternative energy sources.

"Industries are relocating to other countries because they get no support here," he said.

And he said the Lib Dems would open up their green policies to an independent audit so people could judge how effective they were.

The organisation used for the audit would be independent of both the Liberal Democrats and pressure groups and the results would be made public, he promised.