Brokers have always had an arrangement fee 'kickback' from the insurer, but I have a feeling that they are soon going to be required to say what their cut is.
Your broker may just be slightly ahead of the game in implementing this new 'transparency'.
I've just done my bike insurance renewal - after all sorts of haggling I got my broker (Swinton) down to the same price as last year (about £115).
In amongst all the legal stuff he then had to read out was that there was a £25 broker fee (included in the £115) - so it seems it is a new 'transparency' rule.
Grumpy - it's not a new extra charge - it's merely that the brokers now appear to have to tell us what part of the overall premium goes to them (whereas previously it was hidden in the total price).
The only thing that matters is the 'total cost to the customer' which they will still tell you as a single figure.