Last week Caroline Lucas made both her maiden speech in the House of Commons and the front page of The Independent newspaper this week. Her speech was a brilliant account of Green politics.

Greens have always sought to deal with the cause not the symptom. Greens believe in a politics that stands for people and the planet against abstract systems. Greens would transform the economic system that is at the root of both the systematic exploitation of people and the environmental crisis. Green politics aims to use the economy and politics to promote human well-being and a sustainable relationship with the environment.

Lucas’ speech presents a comprehensive Green politics which would deliver not just a better environment, but a transformed society. The environment is a vital concern, but the Green critique goes deeper. Green politics is humanist at root. A politics that puts people at its heart, not the abstract concerns of the authoritarian left and free market right. This is a politics that delivers all the outcomes sought by environmentalists. It is a complementary, not a competing agenda.

It is not surprising that Lucas’ maiden speech reflected this concern. She has always been a politician of substance, with a wide portfolio of interests. Her long-term commitment to Palestine and poverty show commitment to a broader Green politics. Having delivered the obligatory acclamation of her predecessor, she describes the charms of Brighton. By prioritising the important work done by public and voluntary sector workers she shows where her concerns lie. Far from the current government’s obsession with cutting vital services Lucas supports not just popular professions in health and education, but also those faced with difficult work and little appreciation such as social workers and border agency staff.

This commitment to a broad Green agenda was vital to Lucas being elected. Where Greens are seen as a party only of the environment, their vote diminished. In Norwich, where Greens doubled their vote, the party has been campaigning on closure of day care centres and protecting public services. The defining moment in electing Lucas was the launch of a Green economic strategy: the Green New Deal.

While the media talked about how a recession would dent the Green vote, the Green New Deal provided a Green economic response. This was vital in defining Green ideology. Greens set out how they would re-direct the economy towards social justice and zero carbon. Instead of treating the symptoms of a broken economic system, Greens outlined how they would rebuild the economy with people and the planet at its heart.

This included millions of jobs increasing energy efficiency, a radical reform of the banks, changes to the international trade system, and replacing the primacy of measuring economic growth with measurement of well-being. The Green New Deal would herald a new age of economic and social development marked by lower levels of inequality, an end to environmental destruction and substantial increases in human happiness.

Greens now have the opportunity to become the party of progressive politics. This progressive politics, the politics of trade unionists, community activists, environmentalists, anti-poverty campaigners and feminists has needed leadership since Labour’s move to the right in the mid-1990s. Those who want to see an active state and strong civil society changing the world for the better have a natural home in the Green party. All that has been needed is an electoral breakthrough, like that in Brighton Pavilion allied to an approach to politics such as that outlined by Lucas in her speech.

While some elements of the Liberal Democrats have sought to occupy this space, their decision to support a Tory-led government whose aim is to slash the state fundamentally undermines this. The Labour left have for some time harboured a dream of ‘reclaiming the Labour party’ – but given their inability to nominate a candidate in two leadership elections, this seems highly unlikely. Only Greens can offer leadership to progressive politics.

Caroline Lucas’ speech starts the process of seizing this opportunity. Given a parliamentary term to make the case for a new alignment of progressive politics around the Green party, Lucas may be able to create the momentum for radical change in UK politics. No longer will those concerned with human rights, human well-being and the lives of distant others and future generations have to hold their noses and vote Labour or Liberal Democrat. The real change begins here. And as Lucas points out the Labour party took power only 30 years after entering parliament. A change that would send political shockwaves throughout the world.