There should be no loss of your no claims discount as the liability for the pothole rests with the council.
However, I hear some councils are trying to wriggle out of their responsibility if they were unaware of the problem pothole prior to the accident, but I think that’s a bit of a cop out. Big holes don’t appear overnight and the onus for frequently surveying the roads rests with them, not the general public.
We have craters which have grown to as big as 3 ft long and ten inches deep here. It doesn’t take long for these to open up, but it would be whole lot cheaper and safer if they filled them in sooner!