Princess Diana's former butler has pondered whether Prince William being given more sausages for breakfast when he was a child played a part in their played a part in their fractious relationship as adults.

Paul Burrell claims the Duke of Sussex would become confused and complain when he was young that his older brother got bigger breakfasts.

The 64-year-old claims after the young prince asked why that once, a nanny for the pair told him the now-Prince of Wales needed 'filling up more' as he would be 'King one day'.

Mr Burrell, who acted as butler for the Princess of Wales for 10 years, said it could have been an early display of the dynamic between the two feuding siblings that dominates today.

Mr Burrell, who was present during William and Harry's childhood, said there were signs of an early rivalry between the princes.  

“When I look back now, I think maybe I was glimpsing the dynamic at play,” he told the Sun.

“One time I saw the nanny give William three sausages at breakfast and Harry had two. And Harry would look at his plate and say, how come he gets three? And I only get two.”

Mr Burrell added that when the nanny responded about the pecking order between the two brothers the now-Duke of Sussex would 'fall quiet and suck it up'.

The former member of the Royal Household said despite Diana seeing the boys as 'absolutely equal', he believes the hierarchy within the Firm that puts William first has caused resentment from Harry.

He said that the Duke 'found it tough living up to the standard set by William' and that this became more stark when he attended Eton against his mother's wishes.

Mr Burrell said Diana had felt Harry would be unjustly compared to his older brother if he went to the independent school, and that this turned out to be the case.

The father-of-two said that William was 'brighter' than his younger brother, and that while the future King was 'measured and stoic', Harry took to playing the clown to get noticed.

He added that he no longer recognises the Harry who is in the public eye today to the young boy he saw grow up in the Royal Household, saying: 'He's clearly hurt and angry at being "the spare" and so he's lashing out from that place.'

Meanwhile, Mr Burrell claimed that the relationship between the Fab Four - the Sussexes and the Cambridges -  worsened over 'house envy'.

He claimed that Meghan, who was then living in Nottingham Cottage while the Cambridges were in Kensington Palace, 'got a sight of everything Kate and William enjoyed... she realised she wasn't in the top tier'.