The Duke and Duchess of Cambridge will name a baby daughter Diana, according to royal biographer Andrew Morton.
The author - who wrote a biography of Prince William's mum the Princess of Wales, which revealed the truth behind her strained royal relationships - said a daughter would be given the name Elizabeth Diana Windsor.
Mr Morton told The Sun on Sunday reporter Ben Griffiths: "Close friends to William and Kate have told me that if it is a girl they want to name the baby after Diana."
He said: "They discussed girls' names before George was born and now they're hoping the next one is a girl so they can carry out their wish to honour William's mother. They're not too thrilled at the thought it will be shortened to Princess Di. But it won't change their minds." Mr Morton added that the couple had to consider that many royals would be furious if the baby was christened Diana Elizabeth, due to the 'hostility' between Diana and the royal family.
In November 2010, William gave Kate the engagement ring that once belonged to Diana, saying it was 'my way of making sure my mother didn't miss out on today and the excitement'.
After Mr Morton's claims, Elizabeth became 10/1 favourite for the name with Coral bookmakers. James is second at 11/1, Victoria third at 12/1 and Alexandra fourth at 14/1. Kate's latest pregnancy was announced on September 8, as it was revealed she was suffering from very acute morning sickness and being treated by doctors at Kensington Palace.
The couple are choosing to base their family in Norfolk, but the new baby will be delivered at St Mary's Hospital in Paddington, central London, where Prince George was born in July 2013.
On Friday, Clarence House said Kate was recovering from hyperemesis gravidarum and could be back in public at official royal duties in November.