In the early 1900s the trade unions set up the Labour Representation Committee to do what it says on the tin - represent workers in the political arena.
That morphed into the Labour Party.
Without rich supporters the unions started a small levy on their thousands of members to fund their party.
That arrangement is still in place.
Hundreds of thousands of members of affiliated unions still pay what is called the 'political levy'.
For that they get a type of associated membership which gives them a vote in the electoral college that chooses the Labour Party leader and deputy leader.
It's not one big donation - its lot's of tiny membership fees. Union members can opt out of paying.
It's transparent and built into the party's and the unions' democratically decided rules.
It is nothing like the huge donations from super-rich individuals, stitched-up in secret meetings and coming from offshore tax havens, that fund the Conservative Party.
Every time someone repeats Tory spin about Labour and union funding we must point them to these facts.