The Duchess of Cambridge has gone into labour with her third child.

Catherine and the Duke of Cambridge arrived at the Lindo Wing at St Mary's Hospital, Paddington, in central London shortly before 6:00 BST on Monday.

Her Royal Highness The Duchess of Cambridge was admitted to St. Mary’s Hospital, Paddington, London earlier this morning in the early stages of labour.

The Duchess travelled by car from Kensington Palace to the Lindo Wing at St. Mary’s Hospital with The Duke of Cambridge.

— Kensington Palace (@KensingtonRoyal) April 23, 2018

Catherine has been on maternity leave since making a last royal visit to a charity lunch in London on 22 March.

The baby, whose title will be HRH Prince or Princess of Cambridge, will be fifth in line to the throne and the Queen's sixth great-grandchild.

The birth will be announced with an email to the press and a celebratory tweet posted on the Kensington Palace Twitter feed.

There will also be the traditional custom of placing a framed paper proclamation on an ornate gold stand behind the iron railings of Buckingham Palace.

As with her first two children, Kate is hoping for a natural birth and does not know whether she is having a boy or a girl.

Consultant obstetrician Guy Thorpe-Beeston and consultant gynaecologist Alan Farthing are the two senior royal doctors overseeing the birth.

Both were called in for the arrival of Prince George in 2013 and Princess Charlotte in 2015.

Favourite names at the bookmakers include Mary, Alice, Alexandra, Elizabeth and Victoria for a girl and Arthur, Albert, Frederick, James and Philip for a boy.

The duchess's pregnancy was announced in October.

If, as expected, the child is born on Monday, St George's Day, they will share their birthday with Lady Gabriella Windsor - the daughter of Prince and Princess Michael of Kent, who was born at the Lindo Wing on 23 April 1981.

The baby has just missed arriving on the Queen's birthday, which was on Saturday.

Happy 92nd Birthday to Her Majesty The Queen!#QueensBirthday #HappyBirthdayHerMajesty pic.twitter.com/6FqHbsJmyN

— The Royal Family (@RoyalFamily) April 21, 2018