The Duke and Duchess of Cambridge are expecting their third child, Kensington Palace has announced.

According to the BBC, the Queen and both the Royal family and the Middleton family are said to be “delighted with the news”.

The Duchess is again suffering from severe morning sickness, which affected her during her two previous pregnancies.

Her sickness has stopped her attending a planned engagement at the Hornsey Road Children’s Centre in London today.

She was due to hear a discussion about perinatal mental health when she visited the centre, which provides families with support services delivered by the charity Family Action, of which the Queen is patron.

Perinatal mental health problems can occur during pregnancy or in the first year following the birth of a child, and can affect up to 20% of women, experts say.

Kate and Prince William gave birth to their oldest child Prince George in July 2013 and their daughter Charlotte in May 2015. George will begin his first day at school this week.