plant ID please

This has sprung up - and I use the term advisedly because it's growing like stink - in a patch of ground formerly covered by a spreading leylandii, where absolutely nothing else is trying to grow. In solitary splendour it has grown about 30cm in the last week, and has now attached itself firmly to the adjacent fence with twining tendrils like a clematis. It must be a weed, I know that, for nothing else could grow that fast, but I am reluctant to dispatch it until I know what it is or can see what it lans to do, as I have never met it before. Does anybody recognise it? Its leaves were rather grey and felty to begin with, but they're greener and smoother now, although you can still see it's covered in fine hairs. Surely one of you can tell me what it is...?
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White briony, gets very large through the season with little white flowers and red berries that are not for eating.
In the sticks near Peterborough
I am with you and think it's a weed, I have found several very similar plants in my garden this week and I have a vague recollection of one of them six foot up my trellis last year smothering everything else. I am sure an expert will soon advise us both.
Only 6 foot DD? That must be the dwarf variety
In the sticks near Peterborough
I did keep hacking at it Nut!
In the sticks near Peterborough
Thanks all. Guess I'd better dig it up before it gets bigger than me then.
Big root a bit like a parsnip Pegletbee, also not to be eaten
In the sticks near Peterborough
I promise not to eat any of it NC. Thanks again for the info.