Cucumber leaf issue

What's wrong here please.

 

Oh just guessing, but I think it might be something like thrips or some insect in the growing point.
They damage the leaves as they are forming but dont do any serious damage.
I've got a feeling it will grow out of it, but you could try having a close look in that area where the new leaves are forming, and squash anything you find moving.

 

Thank you Pete, my eyes are not as good as they used to be, I will put the wife's glasses on and have a look tomorrow and report back, many thanks.

 

@pete
Hi Pete I had a better look today, i noticed some very small insects running up and down the supporting canes i couldn't see anything on the leaf, if it gets any worse i will give them a spray with something many thanks .