Scilla siberica.

Lovely plant, similar in colour to my agapanthus. Is scilla siberica invasive in the uk?

No. It self sows a little if happy but that is an advantage. It doesn't spread in the wild, so it can't be termed invasive.

That's it! Thanks floral. I knew someone else would recognize them.

I'm far from the UK, but this clump has enlarged, and a few have come up close to the main one but not a nuisance at all.