Sources reveal the Duchess of Cambridge's due date

Kate will give birth to her third child weeks before Harry and Meghan's wedding. Photo / Getty Images

The Duchess of Cambridge could be set to give the United Kingdom a patriotic boost by giving birth to her third child on St George's Day.

Kate, 36, is due in April and now sources have told the Sun that her due date is close to the patron saint of England's feast day on the 23rd.

"There's no certainty with due dates of course but the Duchess is working off a date around St George's Day and it would be a lovely patriotic coincidence if he or she were born then," the source said.

If the royal baby does arrive on the feast day, it could reignite calls for April 23 to become a public holiday, reports the Daily Mail.

The idea has been brought up in Parliament every year since 2006 and most other countries have a day off to celebrate their national Saint, such as St Patrick in Ireland.

Kate has a busy time ahead as she prepares to become a mother-of-three just weeks before Harry and Meghan wed at Windsor Castle.

The Duchess will have a newborn on her hands when the couple tie the knot on May 19 and will also be looking after Prince George and Princess Charlotte who are expected to take on the roles of page boy and bridesmaid.

Catherine and her growing baby bump made an apperance at the Royal Foundation Forum. Photo / Getty Images

It comes after a hectic few months for the expectant mother who has had her busiest start to the year to date - completing 38 official engagements so far despite being weeks from giving birth.

Kate, who is more than seven months pregnant, has had a whirlwind calendar - including a jam-packed overseas tour to Sweden and Norway.

During the same period in 2016, Kate had completed seven official engagements, according to the Royal Court Circular.

The Duchess had a busier diary in 2015 - when she was pregnant with Princess Charlotte - completing 13 official engagements.

In the past, she and Prince William have been accused of not pulling their weight, with the couple often completing fewer engagements than older members of the royal family over the course of a year.

Experts say the recent influx of engagements may be due to Kate wanting to help Meghan with her first steps into royal life, as well as the Duchess preparing to take time off after the birth of her third child.