I don't know what kind of light you have been keeping them in, Hywel, but it isn't nearly enough. I would plan on starting over, sowing in as much direct sun as possible, or maximum artificial light. Gradual hardening off might save these, but they are more likely to just collapse. Taking tip cuttings might work, ramping up the sun as quickly as you can after they root.

I'd cut them in half and root the tips and see if the bottoms send out side shoots.
I often find they are more leggy than I'd like.

Thank you both. I'll do as you both suggest - cut them and hope for the best, and also sow more next year and hope we get a better summer with some sunshine :D

I keep forgetting that the UK is a place where--in some years--you can sit out on a south-facing terrace spring through fall, and develop a prison pallor! :)
Ah, well, still probably better for your health than the skin cancer we get if we aren't careful, and scurry from shadow to shadow. :}

skin cancer is a problem for us too Tug as the English/British complexion is pale that goes lobster in the sun. even with an spf of 50+ I burn if I am not careful.

but I like the term prison pallor ;o)

I wish we had a bit more sunshine though .... but not like they're having in southern Europe at the moment :( That's too hot.

Actually, although I had gingery hair in my youth ! (but brown now lol) my skin doesn't burn very much. It's rather dark and sometimes people ask me, even in the winter, where have I been to get a tan ... but it's my natural colour :)