Normally when the toilet is flushed it would re-fill in say a half
minute and you could hear the cistern filling, now its like it fills in
short bursts almost like a tap is being turned and then off, it does
this about 7 times until the valve cuts it off when filled.

Any ideas what would cause this, its just recently started doing this.
No other water is being used at the same time ie dishwasher or washing
machine.