William with Kate as training ends
The Duke of Cambridge is waiting by his wife's side for the imminent birth of his second child after completing a phase of his air ambulance helicopter training early.
Sources had suggested that William might have to make a dash from flying training with his employer, Bond Air Services, to be with Kate if she went into labour.
But he is now on leave from his job until June 1, when he will start a final three-week phase of work before beginning to fly rescue missions with the East Anglian Air Ambulance charity.
Kate is expected to give birth in the coming days and is likely to be at her London home, Kensington Palace.
A Kensington Palace spokesman said: "The Duke of Cambridge has completed the first phase of his in-work air ambulance helicopter pilot training with Bond Air Services earlier than anticipated.
"This is due to a combination of the Duke performing well in the various modules and having very good flying conditions that allowed flight training and assessment to progress more quickly than had been planned.
"His final block of in-work training requires an uninterrupted three-week block of working time and the availability of the new EC145 helicopter that will be used for missions.
"This has always been scheduled to commence on 1st June, following a pre-planned period of official royal engagements in late May, details of which will be announced in due course.
"As he now will not have any further training to complete after returning from paternity leave, he will not return to duties with Bond until that time, and will remain on unpaid leave until then."
The baby's uncle, Prince Harry, may also get to meet his newborn niece or nephew sooner than anticipated.
He had been expected to be overseas when William and Kate's second child was born, but he is now jetting in to the UK for the London Marathon on Sunday.
Harry has been in Australia on attachment with the Australian Defence Force and, after carrying out engagements with his father, the Prince of Wales, in Turkey for the Gallipoli commemorations on April 24 and 25 , he will make a brief trip to the UK to present medals at the London Marathon, before returning to Australia on Monday.
If Kate delivers her baby within this brief window, then Harry will be able to see the new addition to the family before he resumes his duties Down Under.
But royal fans are hoping that the baby - the Queen's fifth great-grandchild - will make an appearance today to coincide with the monarch's 89th birthday.
The Queen is spending the day privately at Windsor Castle, where she has been staying for the past month for Easter Court.
Bookmaker Ladbrokes said punters were betting heavily on the baby being born on the reported due date of April 25 with odds of 7-1, or April 26 with the same odds.
Jessica Bridge, of Ladbrokes, said: "With William around for the birth and Harry back in the UK, punters are putting two and two together and getting very excited over the prospect of a weekend birth."
But with speculation that Kate might go overdue again, April 29 - William and Kate's wedding anniversary - is the most popular date with Ladbrokes.
Alice remains the favourite name, bur Arthur is now at 12-1, having previously been at 20-1 yesterday.
Ms Bridge added: "The gamble on Arthur is interesting, and it looks like it's a case of better late than never for cash to start coming in for a Prince."