No dial tone or incoming calls, tried different (plug in) handset on master socket no change - but broadband connection works. Can there be a network fault that allows broadband connection but not voice on analogue?

Yes, faults can cause just the voice side to become broke.

You'll have to give BT a call to report the fault.... Maybe call them via VoIP - to save you running up a big mobile bill!

Are you on virgin and in the Worthing Hove or Brighton bit of the south coast?
Alan

When this happens it's usually a line card in the exchange. Your phone line must be intact all the way to the exchange as you are receiving a broadband signal

I had a similar problem at my old house. Openreach were doing a repair on corroded pairs in the street and my line became disconnected although the broadband connection still worked.
Only half of the pair was connected because they engineer hadn't reconnected the other half so I could get a broadband signal but the line was dead for voice calls, thankfully a cup of coffee got it sorted for me.