Sarah Ferguson's five-word code to friends to show true feelings about Prince Andrew

A Royal biographer has claimed that Sarah Ferguson employed a cryptic five-word phrase to signal to her friends that her marriage to Prince Andrew, the Duke of York, was nearly at an end.

In his latest work 'Entitled: The Rise And Fall Of The House Of York', Andrew Lownie examines the journey of one of the Royal Family's most controversial figures.

Despite withdrawing from Royal duties in 2019 after his disastrous Newsnight appearance, where he discussed his friendship with late convicted sex offender Jeffrey Epstein, Andrew has continued to face mounting controversies.

READ MORE: Palace secrets behind closed doors - royal butler reveals Prince Harry and Kate bombshells

READ MORE: King Charles officially kicks off Balmoral summer holiday with cheeky pony

Fears are growing that matters could deteriorate further with the publication of Mr Lownie's unauthorised biography of the 65-year-old.

Alongside his royal career, the book explores Andrew's decade-long marriage with Sarah and reveals the coded language she reportedly began using with friends to discreetly communicate her relationship struggles.

Sarah and Andrewmarried in 1986 but separated in 1992, before their official divorce in 1996. However, the former couple have maintained an amicable relationship since.

Mr Lownie alleged in his book: "By now Sarah was using a secret code with her closest friends to let them know that her relationship with Andrew was crumbling. Said one: 'When things were getting very rough she'd say 'The ranch is getting closer.' A reference to her mother's flit to Argentina.'"

The "flit" Mr Lownie refers to is when Sarah's mum, Susan Barrantes (formerly Ferguson and Wright), left her family to start a romance with Argentinian polo player Hector Barrantes. Hector passed away in 1990, eight years before Susan, who is reportedly buried next to him.

Mr Lownie's book release has reportedly heightened concerns within the Royal Family about Andrew potentially getting tangled up in more negative stories.

Journalist Richard Eden expressed his thoughts in a new television documentary about Andrew. He said: "Who knows what could come out? I think the Royal Family still lives in fear, frankly, of what could come out."

In the run-up to the book's launch, Mr Lownie has been discussing the attention it has garnered, and how it took him four years to finish, after submitting hundreds of Freedom of Information requests to government departments.

He alleged to Sky that his applications were rejected, while addressing the widespread uproar around his work before it became widely accessible.

Mr Lownie told the broadcaster: "Clearly there are details that people have picked up on and run with. And you know, that's inevitable in these sort of books. If they're to earn our trust and support, they have to show that they are not hiding things - that they are behaving well."

Mr Lownie has also tackled the question of whether Andrew might return to public duties following a YouGov poll which revealed the Duke remains the least popular Royal.

The findings showed that 87 percent of respondents hold a negative opinion of him, whilst merely five percent view him favourably, with disapproval ratings climbing among younger demographics.

Mr Lownie remarked: "I don't think he has any public future. I would say his private future is pretty limited too. I mean, he lives in Royal Lodge [on the Windsor Estate], he plays golf, watches TV, and presumably sees his grandchildren ... he's living the life of a retired man."