This is my three-point plan for standing up to the far right and the billionaire bullies | Sadiq Khan

Progressives across the western world face a century-defining challenge – and the stakes for liberal democracy couldn’t be higher.

The far right is on the march. From Switzerland and Sweden to Hungary, Austria and Italy, European nations are coming under the influence of extreme nativist parties that are hostile to democratic institutions, immigrant populations and fact-based journalism.

By exploiting economic concerns and a growing distrust of political and media institutions, these reactionary populists have been able to attract new supporters. In Germany, the AfD is on course for a breakthrough in next month’s federal elections. In France, the National Rally is topping presidential polls. And, of course, in the US, Donald Trump is back.

These are deeply worrying times, especially if you’re a member of a minority community. As historians and commentators increasingly find echoes of the 1920s and 30s in the present day, we cannot afford to throw in the towel. We must make a renewed and concerted effort to confront these forces and expose them for what they are: opportunists who seek to divide people for personal and political gain. Not to mention their financial backers who selfishly choose to put the profits of their companies over the interests of our democracies.

We need to be frank about who we’re dealing with. I agree with the government that we need to be pragmatic on the international stage, but progressives around the world should never yield ground to the far right, nor be afraid to speak truth to power.

We also need a serious strategy to halt the extremists in their tracks. First, we must ratchet up the pressure on social media companies to tackle lies, hate and misinformation. The situation has been made far worse by the actions of Elon Musk, who has reinstated the accounts of far-right figures, including Tommy Robinson. According to the Center for Countering Digital Hate, Robinson racked up 434m views on X during the riots last summer as he called for “mass deportations”.

Responsible tech has enormous potential to enhance our health, environment and quality of life – and just this week I joined the prime minister as he announced his new AI strategy, which will help to turbocharge economic growth. But it’s high time governments around the world forced social media companies to clean up their act. There has been a dereliction of duty to confront the harm they’re causing, which cannot continue.

A billionaire bully shouldn’t be able to use his social media platform as a propaganda tool to amplify lies and advance the cause of the far right. Nor should social media companies be able to evade responsibility for algorithms that maximise – and monetise – hate. Lawmakers and regulators across the world need to get tough, especially as Meta – the owner of Facebook and Instagram – bends the knee to the incoming Trump administration by removing independent factcheckers. In the UK, the Online Safety Act should be the floor, not the ceiling, of what’s required.

Second, we should challenge so-called mainstream politicians who are normalising the ideas and language of the far right. We’ve recently seen senior members of the shadow cabinet using dehumanising language that used to be considered alien to British values and political debate. But the Overton window is shifting before our eyes – leading to extreme arguments becoming acceptable in our public discourse. This only emboldens the far right.

Finally, the centre left – and liberal democracy more widely – need to prove we can still deliver for working people. We must take a hard look at our own political shortcomings and have the self-awareness to acknowledge that while social media is fuelling racist populism and polarisation, it’s not the only reason people are gravitating to extremes.

A decades-long rise in inequality, massively exacerbated under the last government, combined with falling living standards and a failure to build more integrated communities, is creating fertile conditions for the far right. It’s up to us to demonstrate that democracy and equality are still the path to prosperity and a better future.

We should be in no doubt, this is a perilous moment. The spectre of a resurgent fascism haunts the west. But in London, we’ve shown that we can defeat the politics of fear and division, with hope, unity and practical policies – such as free school meals, fares freezes, free skills training and social housebuilding that improve people’s lives. To ward off the far right, we must be unflinching in defence of our democracy and values, and in our determination to enhance the welfare and material conditions of our communities.

At a national level, our Labour government is right to be investing in and reforming our schools, hospitals and other public services to show mainstream politics is a force for good. And in London, we’ll continue to stand tall as a beacon of inclusion. But there is more we can – and must – do to inoculate our societies against the virus of far-right populism. History shows us the time to act is now.