I would suggest it could be a Phacelia which is grown for 'green manure' on some farms. Are you close to farmland? If it is the bees do adore this and seems a shame that it is usually ploughed in before it flowers!
Do a search on Google and compare the results to yours.

I don't think its that. We had some self sown phacelia and the flower buds uncurled from a shape like a catherine wheel, quite unlike anything else I'd seen. Its very pretty though. It looks a bit like a dainty little version of Campanula glomerata - its not than but could it be another campanula? I hope somebody can identify it.

Well, the flowers are similar Honeysuckle, but the stems and leaves seem very different. Never heard of Phacelia before, so had an interesting read, thanks.

Is it maybe a species of Gilia?

Well done Tugbrethil. I've had a look and it seems to be Gilia Capitata. Thank you so much. It's been called the 'little blue flower' for 6 or 7 years now. :-)

See how much we all learn on GOY! I have never come across Gilia before and having looked it up (and seen yours) I think I might have a go with it next year. Well done Tugbrethil.

Thank you! :)