They will be ok, but you need to act now as this weakens the plant and may kill it. So start by removing any infected leaves as you spot them, now and very two weeks you can spray with a systemic action fungicide. Also when the hollyhock dies down, clear away any infected leaves as they will harbour it. Keep the area weed free. Do not put leaves in your compost. This works for me.

Thanks for that but having just had a good look at it the majority of its leaves have rust. Shall I just dig it up and throw away?
I do have some more hardening off that I grew from seed so I could replace them. If I do this should I put my own in a different part of the garden?
Sorry for so many questions.
Polly

I would perhaps try a different part of the garden but I would also spray them.

We have almost always had rust on our hollyhocks. I thought it was almost unavoidable. But they never die on us.