Kate Middleton is in labour: what happens next?

The Queen and senior members of the Royal family will be the first to be told about the birth, along with Kate’s family – if they are not at the hospital.

Then a royal aide will take a bulletin, signed by doctors, from the hospital to Buckingham palace under police escort. The short drive is likely to be broadcast live to television viewers worldwide.

The bulletin – which will give the baby’s gender and time of birth - will then be displayed for the public to see. It will read something like ‘The Duchess of Cambridge was safely delivered of a prince / princess.’

Traditionally, news of royal births and deaths has been attached to the railings of the Palace, but in this case it will be posted on an ornate easel placed in the frontcourt of the Palace.

At the same time, the official Royal Twitter and Facebook accounts will announce the news online – this is a first in the history of royal births.

The next time William and Kate are expected to appear in public is on the steps of the hospital with their newborn.

The baby will be the Queen's third great-grandchild and, under new laws, the baby will remain third in line to the throne regardless of gender. It will be expected to take the throne following reigns by Prince Charles and then Prince William. Prince Harry will be demoted to fourth in line.

The baby’s title will be: His or Her Royal Highness Prince or Princess (the baby's name) of Cambridge. However, it could take as long as 10 days before the child's name is announced.

It is understood that William and Kate have chosen not to learn the sex of their baby until it is born, and - although they have a shortlist – a name has not yet been decided. The best odds, according to the public, are Alexandra (the Queen's middle name) and George (the name of six British kings).

British babies born the same day as Kate and Will's baby will each receive a ‘lucky’ silver penny, bearing a shield of the Royal Arms.