“Don’t mistake debate for division. Don’t mistake democracy for disunity.”

Those were the words of John McDonnell last September and, though he and I often disagree, I was with him on this. Labour had just lost badly, and there needed to be a discussion in which no ideas were off the table.

Fast-forward 10 months and the party is as divided and disunited as I can remember. The current leadership has settled into a sectarian comfort zone – the effect of this has been to provoke personal attacks on MPs, a string of death and rape threats and bricks through windows.

This threatens to destroy the party I love and have served as an active member, trade unionist, MP, minister and shadow minister, for 40 years. Betrayal narratives do not unite; they divide and Labour will pay a huge price if this is allowed to continue. But it’s not too late to get our house in order and I know I can unite us again.

I’m a gay, working-class woman from the north of England and proud of who I am. The progress I made was only possible because of the achievements of previous Labour governments giving opportunities to all.

Contrary to our message at the local elections in May, politics is not about taking sides – or, at least, it shouldn’t be. It is about seeking common ground and finding mutual understanding. If centrist Labour members are “Tory scum”, then what of the hard-up pensioner who is uneasy with immigration in his community? What of the hi-tech chief executive donating to charity, the underpaid waitress saving to go to Ascot, or the many other category-defying voters out there?

As a progressive party of principle we must reach out to all. We have an imperative to locate the shared values we have with someone tempted by Ukip or a Tory swing-voter, and to persuade them – not just because it’s the only way we’ll win power, but because it’s the right thing to do. The “kinder politics” will not come just through believing ourselves to hold a monopoly on what is right and moral. This process of mutual respect and understanding must start within the Labour party – and within this leadership contest itself.

Good policy does not come from slogans, but from discourse. This was the central failure of Jeremy’s leadership. Virtually no policy has come from Jeremy. On Trident, for example, most people know that he is anti. But his review on Trident was delayed “because of Brexit”. And then Brexit itself. Jeremy appeared to think that by appearing on television and saying he was seven out of 10 in favour of staying in Europe this would appeal to people who were not sure themselves. Instead it just gave them permission to vote Leave. He should have been making the case to stay in Europe, arguing its merits passionately. He didn’t.

I desperately want us to tackle the big issues of post-Brexit Britain. An economy starved of investment. Our regions suffering and London starting to sputter. I want more tolerance and more respect in our country; I want to give life chances to young people and not stop them going to university.

Despite what social media memes claimed – and some journalists have lazily repeated – I led the backbench rebellion against the introduction of tuition fees, achieving a 10-year cap at £3,000, the creation of the Office for Fair Access and the reintroduction of student grants for the poorest. I voted against the tripling to £9,000.

I want to ensure that our place in the world remains one of influence, because I believe Britain, with its history of democracy, the rule of law, human rights, tolerance and a vibrant economy, is one that can inspire others.

If we fail, the great losers in this will not be the Tories, but the millions of voters Labour exists to help. I am determined to lead the party into a debate that gives us the policies and arguments to save Labour from irrelevance and to put us back into government, where we can make a real difference to people’s lives.