MerylStreep
Thank you everyone. It’s the dreaded bindweed.
She’s not a Gardner so it looks as if I’m going to get my loppers out.
Try wrapping it round a cane and loosening the soil at the base.
You could pull it out more easily but yes, it leaves behind bits of roots which grow into another plant
I've seen a friend wrap a polythene bag round it then spray weed killer into the bag so the weedkiller doesn't touch anything else.
Weedkiller is not good to use generally, but sometimes needs must.
It strangles everything if left to its own devices.