Caroline Lucas was the best PM Britain never had – but she’s shown us how to fix our politics

With our forlorn sense that politics isn’t working and that democracy is broken, as we feel the impacts of both climate change and the decision to leave the European Union in real time, the symbolic answer to our political crisis was always staring us in the face. It was Caroline Lucas, the best prime minister we never had – and, now that she is standing down from her Brighton Pavilion seat, we will never get.

In her bold but gentle way, Lucas embodied the fact that politicians and politics could be better. Not perfect, but good enough. Good enough to know that meaningful change needs a vision of a good society to compel it, alongside bold enough policies and strong enough alliances to get us there.

As the lone Green MP, Lucas embodied those traits and more. Necessity is the mother of invention. She had no choice but to forge alliances with other MPs, to work cooperatively on bills and campaigns on everything from stopping fracking to reversing the ludicrous privatisation of our water companies.

Tony Benn famously said that politics wasn’t about personalities but issues. He was both right and wrong. Politics is about ideas, movement and moments. But it is always about people – about political leaders. We need charismatic, inspiring and purposeful leadership. Not demagogues, but full-time professionals who know their job is to help us build a good society and lead good lives.

The energy and ambition Lucas brought to this pursuit was incredible. Great works are performed, as Samuel Johnson told us, not by strength but by perseverance. Lucas persevered. But she is human. And political humans, as we saw with Jacinda Ardern, New Zealand’s former prime minister, tire and burn out. The system is so broken that no single person can hope to fix it.

Lucas has signalled that she will continue to work tirelessly on climate change, again echoing Benn, who said on leaving Westminster that he was stepping down to spend more time with his politics.

But Westminster, Whitehall and formal politics do matter. They are the sites that set the rules that determine how we regulate society, the economy and our democracy, and how we invest public money. While power has clearly slipped through the fingers of the formal political classes over the past few decades, away from the green benches to blue-chip corporations, big tech companies and, thankfully, to civil society campaigns, the role of formal politics in facing perma-crisis, while insufficient, is still necessary.

We need a political class that can spend and regulate in the right way, that knows its job isn’t to usher in a better world for us, but to create the conditions in which we can build it ourselves. Lucas knew that, but our political and democratic system is so broken it fails to people like her; it wears them down and spits them out. It hoards power at the centre, while opening itself up to the rich and powerful as it turns its back on the rest of us. It lets small factions win control of parties and ruthlessly exploit their position with impunity. It produces identikit MPs who meekly follow the whip in a system that puts party before country.

So, it is bewildering that just when we need more politicians like Lucas, we lose those few we have. But big change was never going to come from within the system. It’s too cosy and too keen to protect its interests over ours. So her leaving isn’t a sign that all is lost, but that change can and must come to a broken edifice. It’s as if the ravens are leaving the Tower of London. Some, such as Lucas and the compelling Labour MP Jon Cruddas, are jumping, others, such as Jamie Driscoll, the serving Labour mayor for North of Tyne, and Beth Winter, a south Wales Labour MP, are being pushed out. But it’s a sign that change is coming.

Everywhere beyond the desiccated walls of parliament, people are picking up the torch: the overwhelming majority of Labour members and unions who know we need proportional representation to create a fairer electoral system that brings in other voices; the thousands of activists and millions of voters who campaigned and voted tactically in the May local elections; the political experiments such as the primary being trialled in south Devon; the huge number of people on the streets for Extinction Rebellion, the companies queueing up for B Corp status to build an economy more in tune with our planet and its people.

Everywhere, except Westminster, change is in the air. The brittle walls of the old politics will tumble. A better politics of collaboration and putting issues before parties looks like Lucas. We know what to do. She has shown us.