removal of phone cable line on window

t45

Hello,
I bought a flat a few years ago and i’m not in the process of replacing windows. The problem is that one of my windows (wooden ledge part) has a telephone cable running through it – i think this must have happened when they converted the property some time ago. I assume that the cable belongs to BT as it runs to a main box outside attached to the brick wall of the property.
I really need to remove this wire ( i assume it is live because I have an active landline) in order to fit the window –
Any advice would be most appreciated.
Would I be liable for a charge if I called out a BT engineer to remove and relocate the line even though I was not responsible for the locating on it in the first place.
Many thanks,

[Deleted User]

You'll be better off posting this in the 'In My Home' board.