Many thanks for your reply and advise. I was hoping that it would be a bit more seamless than that. I cannot afford to pay to both providers for 1 month. I have tried repeatedly to get through to Virgin without any joy. I was also hoping that I could keep my old phone number from day one as we are on our seventies and could do without the extra hassle.
The phone number transfer should be relatively seamless, but it relies on the broadband working.
I hope I haven't caused you any unnecessary concern, but the Virgin installation requires a new cable to be connected to the street and there can sometimes be an unforeseen problem in laying this. Let's hope that doesn't happen to you.