Yarn substitute

I have a pattern that states to use Sunday Knits 5ply yarn (Light worsted weight -137 yds/125m per 50g skein). It is an Australian pattern and I’m not sure what wool, available in UK to use. HELP!

You never have to use the same yarn that is in a pattern. Pick something that is close and can give you a satisfying fabric to match gauge.

I like yarnsub.com as a site for substitute yarns. Here’s a search for Sunday Knits 5ply. I don’t know which one your pattern is calling for but they may be equivalent.
https://yarnsub.com/search?q=sunday+knits+5ply

Yarnsub gives you an idea of the match in gauge as well as drape of the yarns.