Yes. 4 Millbank is where the BBC, ITN and Sky all have Westminster newsrooms, and IIRC, the main bunker for BBC Parliement operations and playout.
I think it's also the designated 'decamp in a crisis' broadcast studio for the BBC National News, isn't it?(looks around at those in the know)
My user name might look like Hatton Cross, but it's pronounced Throatwobbler Mangrove.