Those leaves do not look to me like any Hemp that I have seen growing, but I have seen a plant, that I classify a "weed", growing around here. It usually has a single stem and is shallow rooted and is very easy to pull at any growth stage. It is not something that I have spent much time trying to identify.

Compare with these images for cinquefoil...

Here is a link that might be useful: cinquefoil

Sykotix, boy does that bring back memories I can happily live without! What you've got is good old fashioned Ground Elder(Aegopodium podagraria). Get control of it fast if you only have the one patch of it.

You need a selective herbicide that doesn't kill the grass. It's been a long time since I lived in the UK, so I'm not sure what is on the market, but your local garden centre will be able to advise you as will the RHS (see linky),

Good luck!

Here is a link that might be useful: Ground Elder Advice

Agreed that it's probably Cinquefoil if there are five leaflets & yellow flowers.
If three leaflets then possibly Indian strawberry, mock strawberry. Whatever the case, it's certainly not Ground Elder ("Aegopodium podagraria", aka Bishop's Weed, Goutweed, gout wort, herb gerard, etc.).

If it were (Ground Elder), the best advice you'd get is to take advantage of the situation and eat it!