[Transmission]

The BBC along with everyone else was of course expecting a statement would be likely following the day's events (both the ones obvious to everyone like the family flying to Balmoral and ones behind the scenes like MPs not responding to contact from journalists) but I know that the feeling at the BBC in the early evening was that if it wasn't announced by 1800 then as every minute went by it was getting more and more likely that nothing would be announced that evening and it might be the next day. The revised schedules that were being prepared for that evening were being done with the serious expection that they might still need to be used. I don't think the heads-up they had that "an" announcement was coming was very long at all.

I think they planned to end the rolling coverage at 7 if there’s no statement - then the only bulletin on that day at ten?

Yes, it was regional news at 1900, EastEnders at 1930 and then Celebrity Masterchef and Ambulance replaced by The Repair Shop and a Planet Earth compilation.