March with us today, however old you are and whichever party you support, for the democracy you deserve

Tomorrow more than 100,000 people will march on Parliament Square in Westminster. This will be the biggest rally yet calling for a People’s Vote on any final Brexit deal, following a summer of action that has seen regional events across the country, from Edinburgh to Cardiff, Liverpool to Cambridge.

The focus of this march is very much on how the consequences of Brexit will be felt heaviest and longest by the younger generations, which is why about 10,000 young people will lead the march. The demographic split of the 2016 referendum was striking: three quarters of Brits aged 24 and younger voted Remain; 61 per cent of over 65s wanted to take us out of the European Union.

We write this as two very different people: one, a 75-year-old leader of a political party; and the other, a founder of a movement that brings together young people to fight Brexit. Together, we are uniquely placed to say this: the older generation has forsaken the younger generation.

Young people will have to live with a Brexit that has been imposed on them for decades. Yet so many were denied a voice in 2016 – unlike the Scottish independence referendum, which engaged so many teenagers with politics for the first time, 16 and 17-year-olds were denied a vote.

What’s more, well over 1.5 million people have turned 18 since the referendum and we know that the overwhelming majority of them support Remain, as there are stronger, more vibrant youth campaigns to stay in the EU than there were two and a half years ago.

And those who voted Leave because they were fed up with the failures of government and the political class, now see Brexit only eroding what little trust they had left in our politics. We were promised Brexit would make the NHS better and now doctors are shouting “Please stop!”, while it is increasingly clear that Brexit will betray the Good Friday Agreement.

Those voters wanted more control, a better NHS and to be better off. It's only logical that many of them would now be passionately opposed to a Brexit that removes our influence over EU laws but also keeps us bound by them, hurts the NHS and disproportionately harms the areas of the country that voted to leave the EU. This is reflected in the polls which show the UK has now had enough of Brexit.

In the spirit of what is a cross-party, cross-advocacy campaign that is almost unique – and certainly welcome – in British politics, this march is an opportunity to find common ground. Regardless of whether people voted to stay in or leave the EU, anyone can see that the Chequers proposal is a political and practical failure. An extreme “no deal” – aircraft unable to take off, delays to food and medical supplies – remains unlikely, but whatever is eventually cobbled together will be a seriously bad outcome that would be obviously worse than staying in the EU.

And if that tiny, but unfortunately powerful band of Brexit-at-all-costs ideologues are so sure that their dream of an isolated Britain is what people want, they really should have the confidence to chance their arms and take us on in a People’s Vote.

The march is a demonstration of young people’s anger that their futures have been unnecessarily compromised. But it is also a show of the growing realisation that Brexit is not inevitable, whatever the likes of Boris Johnson and Nigel Farage might want us to believe.

Young people can still look forward to a bright future, but to achieve that, we need to up the pressure for a People’s Vote – and then win it.

Vince Cable is leader of the Liberal Democrats and Femi Oluwole is spokesperson for Our Future Our Choice