Prince William pulled out of a long-standing public engagement yesterday after his wife suffered another debilitating bout of morning sickness.

The development came hours after the prince described the constant discomfort of Kate’s condition. At a charity gala in London, he said: ‘They shouldn’t call it morning sickness – it’s a day and all night sickness.’

Last week the Duchess of Cambridge was in hospital for three days after being diagnosed with hyperemesis gravidarum, which leaves sufferers battling constant nausea and vomiting.

Although Kate, 30, who is estimated to be nine weeks pregnant, was severely dehydrated when she was admitted to the King Edward VII Hospital in London, her condition was stabilised with fluids and nutrients via an intravenous drip. She was sent home on Thursday with a batch of anti-sickness tablets – and strict instructions to rest.

But yesterday she suffered another bout of severe nausea, forcing her husband to cancel his appearance at the British Military Tournament at Earl’s Court.

Her condition was deemed not serious enough to require further hospital treatment, but doctors are keeping a close eye on the duchess to ensure she does not becomes dehydrated again.

The couple are spending their days quietly together at Nottingham Cottage, the home they share in the grounds of Kensington Palace, as Kate attempts to recover. - Daily Mail