[Aunt Sally]

It looks as though it's had a dose of weed killer to me.  I would have said 2,4-D or mecoprop but not sure you can get them now unless someone has some stored in their shed that they are still using. 

I'll look up lawn herbicides might be that they still contain them.

[Aunt Sally]

Yes, selective herbicides for lawns contain them.  They cause twisting of leaves like your picture.  Has anyone been using lawn "weed and feed" or anything like that ?

[Goldfinger]

I've used the same manure over the whole plot this year, except where roots and brassicas have gone.

I had potatoes in the same ground - with the manure, in poly' before the toms' went in, and they had no problems... 

In the green house, I used the same manure again, but didn't plant anything before hand, just went straight in with the toms'. Yet there are no deformities on the tomatoes in there...

The greenhouse is in a slightly more sheltered spot, when the sun gets further round, it's light is then 'dappled' by trees. not like the poly' - on a south facing fence, exposed from sunrise to sunset.

Do you think we can rule out herbicides, and sway more towards heat/ temperture stress...??

[Aunt Sally]

It could be heat stress.  If it is they will grow out of it now that the temperatures are a little cooler.  I should not affect their cropping,