I have a 4 year old B&Q (Cooke & Lewis) mixer tap.
There is a small leak from the middle of the tap. I'm quite handy and thought it was probably a washer, so I attempted to dismantle it to investigate.
However I can't remove the last moving, circular part (see pics). And this is the part that is actually leaking. It doesn't appear to unscrew. I removed the grub screw behind.
Any ideas on how to remove this and fix the leak?