There are people who peddle the line that during a recession, green issues must take second place. As if caring about whether the clothes we wear are produced by child labour is just another fashion, in this week and out the next. As if the environment, or social justice, were a luxury. We know how bogus this line is. We know that in hard times, we are needed all the more.
Ask the people of Sipson. Do they think that stopping their houses being demolished to make way for a new runway for Heathrow is a luxury? Do agency workers laid off without any rights or compensation think that social justice is a middle-class fad? Let us be clear. The Green Party is needed now more than ever.
We know that the changing climate is the greatest threat to humanity. We've known this for a generation. But what is the response of our Government? They say it's up to us. Do your bit. Act on CO2. We're in it together.
No wonder people are confused. This is the greatest threat this country faces. Up there with international terrorism. The rise of fascism in the 1930s. And the Government is telling us to change our light bulbs and turn our washing down to 30 degrees.
Now of course there is a role for individual action. But it is for governments to take the lead. That is why they are there. If we the people could sort it out for ourselves, we wouldn't need government in the first place.
What if William Wilberforce had said: "Could you just cut down a bit? Own one slave instead of two?" What if Emmeline Pankhurst had said: "Maybe our husbands could ask us what we think before they go out to vote?"
This Government has betrayed the people of Britain in the most fundamental way. They have not only failed to protect us. They have lied to us. They have pretended that they have the problem under control. That a few low-energy light bulbs here, a bit of lagging on your loft there, and the problem will go away.
When Neville Chamberlain returned from Munich and waved that scrap of paper promising peace in our time, at least he believed it. Fool that he was, he honestly thought that he had reached a deal with Adolf Hitler. What excuse do our current leaders have?
Caroline Lucas MEP is leader of the Green Party. She will be speaking at the party's spring conference today