?Polemonium pauciflorum and that is a real guess.

I'd agree with polemonium (Jacob's Ladder)

Is that a woody stem I can see in the picture or isn't that related to this plant? Owdboggy, IS there a Polemonium that's evergreen in this country, I thought they're all listed as herbaceous perennial...?

It might be a Sophora - S. microphylla 'Sun King' to be precise - evergreen or semi evergreen, depending on the winter, needs a very sheltered position, but not sure because I can't see flower detail properly.

Ditto, Bamboo, I think you're right, I'd go for Saphora 'Sun King' also.

Sophora microphylla was the first thing i thought of.

I thought of that too, but there was no mention of spines on the branches which ours has.
And most of our Polemoniums keep their leaves over winter.

Goodness, lucky you Owdboggy, you must have some sort of micro climate going there - in London, they disappear totally during the winter. Unless you've got some fancy varieties, which, you being a plantsperson, I'm guessing you might have...

Yep, mine disappear then regrow to around 2 foot every year. Not seen a yellow one either....not to say they don't exist

The one Owdboggy mentioned, Polemonium pauciflorum, does have elongated yellow trumpet flowers, Badfish.

I have Polemonium caeruleum Album - keeps some leaves through out the year. Dies back to a neat little clump and gets going again mid-May.

Thanks so much to you all for your responses. Bamboo is spot on, RHS call it Sophora microphylla Sun King 'Hilsop'. I've also found a better pic of a large one which I'll post.

Owdboggy, mine has no spines. The only reference I could find mentioning spines was for Sophora davidii but this is described as Grey, downy and eventually spiny branches. Small bluish-white pea flowers.
So maybe spines will appear on mine when it is older.