THE Prime Minister was told of Prince Philip's death with a coded message - "Forth Bridge is down".
After the Duke of Edinburgh's death was confirmed by the on-call doctor at Windsor, members of the family were called and told the sad news.
🔵 Read our live blog for the very latest news on Prince Philip's death...The Prime Minister would have been told of Prince Philip's death with the coded message 'Forth Bridge is down'Credit: Getty - Contributor Boris Johnson would have been one of the first to be told - after the immediate family learned of the Duke's death yesterdayCredit: Getty Images - Getty
The PM would have been next in line to be notified.
And upon hearing the code, Boris Johnson would have instantly known of Philip's death.
Finally, officials in relevant arms of Government would have been given the same message.
The British public were informed of the Duke's death just after midday yesterday.
It comes as:Queen shares touching tribute to 'strength & stay' Philip Tower of London lead 40-minute global gun salute in honour of Philip Prince William pulls out of Bafta speech in sign of respect What to expect this weekend as the UK mourns Prince Philip Queen to sign off on funeral arrangements today but will be forced to choose 30 attendees Prince Andrew was the first royal to arrive at Windsor Castle to comfort Queen Duke's death announced to PM with 'Forth Bridge is down' coded message after Royal Family told Queen was 'by Philip's bedside' when he died after final days 'in good form reading in the sun'
A message issued by Buckingham Palace read: "It is with deep sorrow that Her Majesty The Queen announces the death of her beloved husband.
"The Royal Family join with people around the world in mourning his loss."
Royal plans surrounding the Duke's death are known as ‘Operation Forth Bridge’ — a nod to his status as the Duke of Edinburgh, where the landmark rail crossing is located.
Code names for royal deaths were initially introduced to prevent the news leaking before the official announcement.
Using code prevented Buckingham Palace switchboard operators learning of the news before it was made public.The Queen announced her 'beloved' husband of more than 70 years had died yesterdayCredit: AFP - Getty Her Majesty will be forced to keep to a tight list of mourners for the funeral as a result of tough Covid rulesCredit: Getty
However, most royal funeral plans have been so longstanding that the codenames have become common knowledge - the Queen herself is London Bridge, Charles is Menai Bridge, and the Queen Mother was Tay Bridge.
The Duke was involved with the details of Operation Forth Bridge - and specifically asked for a minimum of fuss.
It's understood the Queen will sign off on plans for the funeral today.
She will be forced to choose just 30 attendees as a result of coronavirus restrictions.During a speech for their golden wedding anniversary in 1997, the Queen called her husband 'my strength and stay'Credit: Getty - Contributor She is understood to have been at his side when he diedCredit: Getty - Pool Boris Johnson yesterday paid tribute to the Duke outside No10Credit: No10 Downing Street
Earlier arrangements would have seen thousands of people travel to London and Windsor for a military procession with Philip's coffin.
Those details included his coffin being moved from Windsor to St James’s Palace in London, before being carried through the streets on a gun carriage.
There were also instructions for a 26-mile cortege procession back to Windsor on the day, allowing mourners to line the streets and pay their final respects.
But under Step 2 of Boris Johnson's roadmap out of lockdown, funeral services can only be attended by a maximum of 30 people.
Social distancing must be kept unless they live together or have formed a support bubble.
The Duke previously said he doesn't want a state funeral, it's reported.
The last state funeral for a member of the royal family took place in 1952 following the death of King George VI. The Queen’s father was laid to rest in St George’s Chapel.
Princess Anne pays tribute to Prince Philip saying 'life without him will be completely different' following his death