What is happening to my borage leaves?

[timtam23]

I am trying to grow borage, nasturtiums & pot marigolds together for wildlife and because the colours look gorgeous together.
But some lurgy is taking over my borage, the leaves are becoming blistered and discoloured. Can anyone suggest what is wrong? There are ants on the plants, would they be causing this? No sign of caterpillars or any other pests. The plants are flowering & the flowers, stems etc look OK.
First pic is the top side of the leaves, second is the underside.

Thanks everyone!

At a guess, it looks like powdery mildew.

How bad is the plant? If it's just a bit sickly, cut out the affected foliage, and get rid of it in the bin (not compost). Improve air circulation round the plant and maybe think about moving it to a less damp spot and it should recover. If it's gone into collapse mode, you may have to bin it, I'm afraid.

Thanks for the quick repmy

I'm not sure that it is powdery mildew, the bits which look white in the photo are actually very thin & papery, the plants are in a south facing spot which is sunny with good air circulation (similar site to other plants in nearby houses which are looking 100% healthy )

I have been picking the leaves off but it doesn't seem to stop the blistering on other leaves. No sign of plant collapse which may be a good sign!

Have a look on google images at 'Sclerotinia sclerotiorum leaf'.

There are a couple of pictures that look a bit like what's attacking your plant. I'm almost certain it's some kind of fungus and not ants or other critters.

Thank you - Yes - some of the images do look a lot like my plant. I'm a bit puzzled by the rest of the plant remaining healthy though (leaves have been doing this for a couple of weeks now)
I will assume a fungus, isolate the plants & if no improvement they'll have to be binned

I think it looks like leaf miners, little critters that live inside the leaf and eat tunnels. If you tear a leaf open sort of across the damaged bit you might see the little thing - looks a bit maggoty.

Felyne I think you have got it - I had another look at the leaves I picked off, the papery bits lift off and there are a few little white maggoty things wiggling around between the leaf layers. So I may destroy the worst infested plant but others may get away with having a few leaves removed. Thanks so much!

Well, I was a lot of help here then!! Sorry for getting it so wrong.

Leaf miners ate my chard last year. I had to bin the lot. They made little squiggly lines on the leaves, though - but I guess borage is fleshier and so the outline might not be as defined.

Yes there are no wiggly lines at all which is why I didn't think about leaf miners myself. Thanks for your input shovetheholly the borage is actually looking OK now that I have picked the affected leaves off although one of the plants has no leaves at all...

My borage looks exactly the same!

My beetroot have it too, although this thread has made me realise that I strangely have no borage this year (I planted one plant about 5 years ago and it has self-seeded happily ever since!) I put the flowers in ice cubes for posh pimms