The Labour Party was founded by working people who had come together to form trade unions to get a fair deal at work. But they found that it wasn't only employers that they needed to stand up to, but the government too, and so they founded their own party.
The Labour Party and the trade unions were grassroots organisations, founded to advance our shared aspirations to improve our lives, and save us from exploitation by ruthless employers and oppressive government.
After listening to party members, we entered the Labour leadership contest because of the shared belief that our Party needs to engage with its founding purpose: to fight injustice.
At the National Gallery today in London, the workers there are taking their 35th day of strike action, withdrawing their labour in protest at an employer threatening to privatise their jobs. These are proud public servants, guardians of our national art treasures - and they wish to remain so.
For daring to stand against the fraud of privatisation their leading trade union rep Candy Udwin has been sacked by National Gallery bosses. I have been proud to support their campaigning, join their picket lines, and to call for Candy's reinstatement.
This dispute is what our movement was founded for - to campaign against injustice and support workers defending their rights. That is the simplicity of our timeless task: to stand up against injustice wherever we find it. That notion has driven me throughout my political life - and it's what drove me into standing for Parliament in the first place.
When 120 years ago a former trade unionist entered Parliament to fight injustice, Keir Hardie didn't just fight for workers, he fought for universal suffrage, a universal pension, free education for children, decent homes for all, against powerful monopolies, and for peace.
With over six million members, trade unions are the largest voluntary organisations in the country. They fight against discrimination in the workplace, boost people's living standards, and they save jobs. But trade unions do more than that: as collectives of working people they have supported and often been the driving force for equality legislation, they have supported the anti-war movement, and campaigned for public services and social security.
In the face of rising exploitation of low income people by the banks and payday loan companies, many trade unions have established credit unions. Unite has setup a community section to organise the unemployed, disabled and students.
It Latin America the trade unions have long embraced organising whole communities in social movement trade unionism - and this is what Labour and the trade unions should be doing more.
I am proud to have been a trade union rep, a trade union official and to be an elected representative of the party founded by trade unionists. So I was proud to be standing on a picket line today with PCS members on strike at the National Gallery, and tomorrow with GMB members on strike at the Royal Parks.
There should be no hesitation in backing the basic human right of workers who collectively and democratically decide to withdraw their labour in the face of injustice.
Disgracefully this fundamental right is under attack by the new Conservative government, which seeks to impose a 50% threshold on all union strike ballots. These are laws that do not apply to any other organisations or to any other ballots.
If 50% is to become the new mark of legitimacy in Conservative eyes, then I look forward to hundreds of their councillors resigning, all their police and crime commissioners, all their MEPs, as well as London Mayor Boris Johnson (elected on a meagre 38% turnout).
Of course they won't - and this goes to the heart of the injustice we continue to fight against. It's one rule for those at the top and another for the rest of us.
Whether or not we make the Labour leadership ballot paper, that struggle goes on - just as it does for those strikers today at the National Gallery, and many more in the months and years ahead. Labour must be firmly on their side.
Jeremy Corbyn is the Labour MP for North Islington