Ministers have rehearsed for the Queen's death for the first time with a secret exercise to prepare for 10 days of national mourning, it has emerged.
The run-through, apparently known as Castle Dove, saw Cabinet ministers and Whitehall officials discuss 'D+1', the day after the monarch's death.
The plan, which is reported to be called London Bridge, came in the week that the 92-year-old Queen pulled out of a service at St Paul's Cathedral because she was feeling ill, although it was not in response to any specific fears about her health.
It was the first time politicians had joined civil servants in the same room to discuss the plans, which would involve the Prime Minister speaking to the country, The Sunday Times reported.
A source told the newspaper that the rehearsal was of an 'unprecedented' scale.
They said: 'This is the first time different ministers have come together in one room. Previously it has only been officials.'
Last year the Guardian reported numerous details about the aftermath of the Queen's death, which would see the entire Privy Council assemble to proclaim the new monarch.