I have never felt more like I am living through a defining moment. Everywhere we are asked to pick a side, and division is being stoked by many of our country’s leaders, when they should be leading the way to a finer and kinder understanding of our common humanity.

The natural world is laying down challenges like never before. While we battle a deadly disease and postpone international agreements, climate deadlines are refusing to melt away. These mean the question of how to rebuild a better world after the economic shocks of the pandemic is a decision we will only have one chance to get right.

As we continue through these crises, I want to talk not about what divides us, but about the most positive thing I have seen giving me hope in recent weeks. The principle that could underpin a recovery we can all be proud of: solidarity. We have seen so much community solidarity in Camden in the past three months. From street-by-street mutual aid networks to massively impressive new foodbank and support services growing up from grassroots groups and backed by the council. We have seen much solidarity too within the Black Lives Matter movement and new commitments to better learn our history and remove the glorification of its crimes from our public sphere.

And while we look again at our history, let’s focus more on Britain’s long history of radical ideas and dissent. On how the many different people making our islands their home created the birthplace of trade unions and co-operatives, the home of the NHS, and have been the inspiration for democratic movements around the world.

From the Levellers of the English Civil War, through the Chartists and the campaign for women’s suffrage, to the peace, anti-apartheid and environmental movements, struggles rooted in solidarity are the history of our country too. We can see a revival of campaigning now, on race, housing, health, inequality, policing, our rights and the environment. We’re also seeing a revival in solidarity - not only between activists on the same cause, but between activists making the links between different causes.

This is the kind of solidarity we saw in the 1980s when Lesbians and Gays Support the Miners made the links between the struggles of the miners and the struggle for equality, and the common suppression they faced. The famous Pits and Perverts benefit gig was held at the Electric Ballroom in Camden, and there a National Union of Mineworkers member said to the crowd: “You have worn our badge, ‘Coal not Dole’, and you know what harassment means, as we do. Now we will pin your badge on us; we will support you. It won’t change overnight, but now 140,000 miners know that there are other causes and other problems. We know about Blacks, and gays and nuclear disarmament, and will never be the same.”

The revival (under another Tory government) of questioning the past and the future, of activism and common causes, makes me hopeful we can get through all this with solidarity and make the right decisions about the kind of world we want to rebuild.

• Sian Berry is a member of the London Assembly, councillor for Highgate ward and Green party co-leader.