You've removed the p-trap (so called here in the U.S.) but have you removed and cleaned the gunk from the plug. I'm assiming you have one of the lift rod type plugs. If you have an older rubber plug attached to a chain then disregard. If it's like this (or similar)...
You can buy a liquid for this purpose...have used it in the past but can't remember what it's called....the staff at b & q will know....could be a build up of grease etc ?
You've removed the p-trap (so called here in the U.S.) but have you removed and cleaned the gunk from the plug. I'm assiming you have one of the lift rod type plugs. If you have an older rubber plug attached to a chain then disregard.
Clanad, Your assumption was correct, I do have one of the 'Lift rod types'.
I didn't realize that the whole thing just pulls out, to clean out the gunk.
Got a good vortex going now!
Cheers - Chip.