In a first, the UK ministers rehearsed the death of Queen Elizabeth on Thursday last week after she pulled out of a service at St Paul’s Cathedral due to ill health.
According to media reports, in addition to the senior ministers of Theresa May Cabinet, Home secretary Sajid Javid and leader of the Commons Andrea Leadsom were also reported to have been in the planning session.
The meeting, chaired by Cabinet minister David Lidington, also discussed ten days of national mourning in the aftermath of the Queen's passing.
The rehearsal, dubbed 'Castle Dove', reportedly focused on the day after the Queen's death and when Prime Minister Theresa May would make public statements.
The reports added that though a plan for the Queen's death, known as 'London Bridge' has long been discussed, the last week's exercise was held on an 'unprecedented' scale.
"This is the first time different ministers have come together in one room. Previously it has only been officials," a Whitehall source was quoted as saying by The Times.
The Times quoted another minister as saying that “things have clearly been stepped up because of the ageing process.”