The Queen will be the first member of the Royal family to be told of the birth of the Duke and Duchess of Cambridge's baby.
Prince William will phone his grandmother on an especially encrypted phone to prevent interception from hackers.
The Queen will then wait for the baby to be 'brought to her' rather than visiting him or her at St Mary's Hospital, Paddington, where Kate is due to give birth.
While William is telling his grandmother the happy news, he and Kate's private secretary, Jamie Lowther-Pinkerton, will inform David Cameron, shortly followed by other dignitaries, such as the Archbishop of Canterbury.
Buckingham Palace will announce the baby's arrival to the Commonwealth countries, and the first ministers of Scotland, Wales and Northern Ireland, while a notice for the public will be put on the gates of Buckingham Palace.
The paper reports that depending on the time of day, a 41-gun salute will sound out in Hyde Park within minutes of the news being made public.
The baby was thought to be due on July 13, although the media have been camped outside St Mary's in Paddington since the first week of July, and a car parking space has already been reserved for the Royal mum-to-be.
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