The world's media have been entrenched outside St Mary's Hospital in Paddington for weeks now, but the Duchess of Cambridge could yet give them the slip by giving birth in Reading, it has emerged.
The Duchess, who is thought to have passed her due date, has been staying with her parents in Bucklebury, Berkshire, this week, together with her husband who has time off from his RAF duties.
Aides confirmed that although the Duchess fully intends to have her baby in the private Lindo Wing of St Mary's, a contingency plan for a birth at the Royal Berkshire Hospital, where she was born in 1982, remains in place.
If the Duchess goes into labour while she is staying with her parents and her labour progresses more quickly than expected, her doctors could send her to the Royal Berkshire, which is less than half an hour's drive from Bucklebury, rather than risking the 85km trip to London. It would raise the prospect of the Duchess spending her first night with her baby on a public ward sharing with other mothers, as the hospital does not have a private maternity wing.
A royal source said: "There are contingencies in place for wherever the Duchess happens to be, and one of them is the Royal Berkshire. It is still a possibility that she could give birth there, though that would only be in extremis, as the expectation is that she will go to St Mary's."
The Royal Berkshire Hospital delivers almost 6000 babies a year, and offers women the choice of giving birth on the labour ward or in the Rushey midwife-led birth centre, which has four rooms themed on the four seasons.
Kensington Palace has only ever confirmed that the baby is due in "mid-July", and conflicting reports have put the due date at anything between July 13 and July 19. The Duchess' mother Carole Middleton has reportedly told friends that she believes the baby will be a Leo, meaning she thinks it will arrive on or after July 23.
The couple were said to be "calm" and "relaxed" as they await the arrival of their first child.
Punters splash out on royal birth
Bookmakers are experiencing almost unprecedented levels of activity as punters put money on their predictions about the royal infant.
According to bookmaker Paddy Power, the betting so far predicts a Princess, with a 60/40 split in favour of a baby girl.
Unusual bets on the baby's name have reportedly included Waynetta and Mohammed, but Alexandra remains the firm favourite. Close behind are James and Elizabeth, in honour of the baby's great-grandmother Queen Elizabeth II.
It has also been suggested that the baby could be named Diana after the Duke's mother, the Princess of Wales, who died in a car crash in 1997.