It looks very much like Sisyrinchium Palmifolium to me I have it too and mines just about to flower , also called the bird of paradise Sisyrinchium because of the way the flowers are held at the top of the stem, lovely plant :-)

Thank you Simbad for your reply - your so knowledgeable. It is inbetween my daughter and s-in-l's cottage front path and the next door neighbours. This is only the second year they have lived there and so there are lots of plants that are newly appearing.

Looks like an allium to me. Does it smell of onions when you rub the leaf?? Allium Moly perhaps?

I would agree that that is Allium moly. S. palmatum is much more of an orange coloured flower.

Ooooops looking at it on a bigger screen I think your right Paul, the leaf isn't right for my sisyrinchium its much narrower.

Allium moly. I agree.