The title of today’s May Day rally – ‘workers of the world unite’ – paraphrases the most important thinker of the workers’ movement, Karl Marx, and his call to arms, ‘the proletarians have nothing to lose but their chains. They have a world to win. Workers of the world unite!’

That call for unity in the struggle for socialism is at least as important as it has ever been.

Because this May Day, as we are faced with an economic crisis, a profound crisis in our public, health, and social care services, and a climate crisis of unprecedented scale and unrelenting urgency, we are seeing a ferocious response from the boss class in the pursuit of their interests.

That response is the rising cost of living as their speculation and profit-hoarding drive up prices, and drive down living standards – not only in the UK, but across the globe. It’s the rising racism, as migrants and refugees are scapegoated by the same governments responsible for stoking the wars and climate disasters that people are fleeing. It’s the rising bigotry, as we see, across the world, attacks on the rights and bodily autonomy of women and LGBTQ+ people.

It’s the rising geopolitical tensions, as bombs continue to rain down on Yemen, as the Palestinians endure ever growing oppression, and as the threat of nuclear war intensifies in eastern Europe and the doomsday clock ticks closer to midnight. And it’s the rising global temperatures, as everywhere capitalist governments vacillate in the face of a climate and nature emergency that has seen sea levels rise, species exterminated, and homes and livelihoods destroyed.

Throughout all of this runs one thread: the defence of an economic and political system that prioritises profits against the interests of the overwhelming global majority of people and planet – whether that’s in protecting the big polluters, securing geopolitical influence in the new Cold War, or taking from the wages of the vast majority to pay the profits of a tiny minority.

And where the business-as-usual parties of reaction are incapable of doing that, the boss class unites around the far-right and fascists; as we have seen in Italy, in the inheritors of Musolini, Georgia Meloni’s Fratelli d’Italia. Socialism or barbarism is not just a slogan – it is the choice through which we’re currently living.

We have our work cut out for us but where the cost of living, racism, bigotry, global tensions and temperatures are rising, so, too, are the people. Look at the wave of strike action that started last July. That torch of resistance still burns in the hands of the PCS, the RCN, and NEU who fight for us all as they defend their pay and conditions, and the future of our public services.

Look at all those who have taken to the streets against the fascists – who are shouting ‘say it loud, say it clear, refugees are welcome here,’ or drowning out the hatred of the homophobes. And look at the tens of thousands of protestors, demanding the climate emergency be treated with the urgency it requires.

In response, the bosses are trying to beat us back with assaults on our right to resist – with anti-trade union legislation and attacks on the right to protest. Morgan Trowland and Marcus Decker are worth special mention, two climate activists whose sentences combined run to an unprecedented 5 years and 7 months for the act of participating in a non-violent direct action. They should receive the solidarity of every socialist and progressive.

We must mobilise all parts of our movement to fight this assault with everything we have. We only have to look elsewhere in the world to see they can be defeated, just look at the recent presidential results in Colombia, which overturned decades of subservience to empire. And of course, in Brazil, where Lula – unjustly jailed on trumped-up charges – is once again providing leadership not only to Brazil, but progressive opinion across the globe.

To win these struggles means unity. We must refuse to be divided and stand with every worker under attack, whether they are migrants, women, LGBTQ+, disabled, people of colour, or simply striking to protect themselves from low pay, poor conditions and insecurity. We need unity in action, with far more coordinated initiatives on the left that build solidarity through our shared struggles and demand the socialist solutions to the crises we face.

And we need unity across borders, continuing to support our comrades across the world, from Palestine to Peru, who are fighting for justice, democracy, and their right to a life free of exploitation. Angela Davies said ‘optimism is a political act. You have to act as if it were possible to radically transform the world. And you have to do it all the time.’

Well, on this May Day, I am optimistic because it’s not only possible; it’s necessary; and across the globe people are forcing that transformation. We must join them. Workers of the world unite, you have nothing to lose but your chains – and you have a world to win.