What is this fungus and how to treat it?

I went to visit my folks in London over the weekend and they said that their plant has been suffering from what looks like some fungus.

I tried to scrape it off but it doesn't come off easily, and it's affected a lot of the plant(s) on the side of the fence.

I've got a photo attached here. I don't even know what the plant is.
How can we treat it? (And what is the plant?)

 

Its just a mosaic fungus or mildew, I should not worry about it, it may look unsightly but the plant will not come to any harm.

If u must do anything remove affected leaves and burn them.

 

Looks more like downy mildew to me, whatever it is, treat with a systemic fungicide.

 

Thanks. I hope the plant doesn't die though. Will have a look in the garden centre. Any particular brand? Presumably there's just one type of fungicide, and I'll just spray that.