Lucas, one of the party’s two MEPs, said Greens were the only politicians who were being “honest” with the public about the scale of the threat posed by global warming.
“As the vital Copenhagen climate summit draws closer, it’s clear that the current level of ambition will not deliver anything like the speed and scale of the emission cuts that we so urgently need,” she said, referring to the international conference taking place in December.
“In a few years, people will look back bewildered and angry that – knowing what they knew now – none of the other main political parties in Britain confronted the most critical issue of our time.
“They have pretended that they have the problem under control, that a few low-energy lightbulbs here, a bit of lagging on your loft there, and the problem is solved. And that to do anything more is either unnecessary or involves too much ‘sacrifice’.
“We’ve got news for them: a transition to a post-carbon world doesn’t have to be about sacrifice.
“It’s about jobs, it’s about a more equal society, and it’s about a way of life with the potential to be far more fulfilling than the turbo-charged consumerism which is peddled by politicians today.
“And that’s why we say that our government’s inaction is nothing less than a political crime.”
The conference is taking place adjacent to the Brighton Pavilion constituency in which Lucas is standing at the general election. She hopes to become Britain’s first Green MP and in 2005 she came second, polling 22% of the vote.
She told members the Greens got more city votes in the European elections than any other party, that the party increased its share of the vote by 44% and that, at a time when “the image of politics and parties could hardly be lower”, the Greens had gained 1,000 new members in the last six weeks.
In a speech that strayed well beyond environmental issues, Lucas said that, “for years”, her party had been warning against “the lethal cocktail of liberalisation and deregulation which has fuelled this recession”.
And she also called for far-reaching reforms to the Westminster political system, including fairer funding for political parties, a ban on “mega-donations”, tougher freedom of information legislation, and electoral reform.
“The expenses scandal isn’t a freak accident of an otherwise healthy body politic,” she said.
“It’s a symptom of a system that is wholly dysfunctional. We’re being governed by a political elite that has stopped listening.
“Too many MPs seem more interested in changing their homes than in changing the world. We need to make Westminster alive again with political ideas.”