East Kent chalk flower

I saw this whilst up on the cliff tops yesterday.  I have tried to find out the name  but have not been successful so here is my unnamed entry for the first wildflower challenge of this year, thank you Miranda.
There are a few wild flowers which seem to be particular to the chalk cliffs of East Kent,  perhaps this is one.
PS.  There is also a bee which seems to be attracted to the flower.

The consensus seems to be that it's a Wall flower, it certainly does look like one.