An unauthorised new biography of Prince Charles paints a picture of a capricious man who is obsessed with the public’s opinion of him, whose lavish spending reveals a royal utterly divorced from the life of ordinary people.

According to Tom Bower’s Rebel Prince, published on Thursday by William Collins, Charles once “shrieked” and “trembled” at the sight of an unknown plastic substance covering his dinner, only to be told “It’s cling film, darling,” by Camilla. On another occasion, Bower claims the prince brought his own mattress, toilet seat, Kleenex Velvet toilet paper and two “landscapes of the Scottish Highlands” when visiting a friend in north-east England.

The biography also alleges that Charles took a trip on the royal train from Highgrove to Penrith to visit a pub, a journey that cost £18,916; at another time, the prince reportedly complained in his journal after flying Club Class to Hong Kong in a chartered British Airway plane: “It took me some time to realise … that this was not first class (!) although it puzzled me as to why the seat seemed so uncomfortable. Such is the end of Empire, I sighed to myself.”

According to Bower, the prince has arrived at functions with his own pre-mixed martinis carried by a police officer

Bower, who has previously written unauthorised biographies of names including Tony Blair, Richard Branson and Mohamed Fayed, says he interviewed more than 120 people for his biography of Charles, who he claims has “resorted to machination and media manipulation to restore his position” since 1997. The prince, Bower writes, “presides at the centre of a court with no place for democracy or dissenting views … like some feudal lord”.

Charles’ army of employees – Bowers claims that he has more than 120 staff – include three footmen to escort visitors to his office, “each responsible for a short segment of corridor”; four valets to help him change his clothes up to five times a day; four gardeners who “lie flat, nose down on a trailer” to hand pluck weeds, because of the prince’s hatred of pesticides; and “retired Indian servicemen … deployed to prowl through the undergrowth at night with torches and handpick slugs from the plants of leaves”. According to Bower, the prince has arrived at functions with his own pre-mixed martinis carried by a police officer, with an aide delivering a bag containing the food he would eat.

Charles is obsessed with public opinion, Bower claims, even once hurling a dinner plate to the floor at a dinner party after learning of his low popularity ratings. “‘Mama down the road,’ he told a visitor, ‘reads newspapers; I don’t. It would drive me mad,” writes Bower, who also claims that Charles had a habit of throwing objects at the radio when “enraged by an item … The set was always being repaired.”

The book also details a meeting between the prince and Peter Mandelson, during which the Blairite former minister allegedly told Charles that the public thought he was “rather glum and dispirited”, which had “a dampening effect” on their opinion of him.

“After Mandelson had left, he beseeched Camilla, ‘Is that true? Is that true?’ ‘I don’t think any of us can cope with you asking that question over and over again for the next month,’ she replied,” writes Bower. In the wake of Diana’s death, writes Bower, Charles was “paralysed by guilt”, chanting: “They’re all going to blame me, aren’t they? The world’s going to go completely mad.”

His portrait is of a man discontent with his lot. “Even my office is not the right temperature. Why do I have to put up with this? It makes my life so unbearable,” the prince is quoted as saying to an assistant. Bower quotes one friend describing Charles as “an Olympian whinger”; Charles himself is quoted as saying in 2004: “Nobody knows what utter hell it is to be Prince of Wales.”

Bower claims that access to Charles was sold “to raise money for his many charities and to indulge in ostentatious luxury”, with Turkish billionaire Cem Uzan allegedly paying £200,000 for his wife to sit next to the prince at a dinner in 2000, and American oil tycoon Armand Hammer spending approximately £40m over several years on Charles’ charities and personal expenses, in an attempt to rehabilitate his own public image.

The biography details the prince’s fractious relationship with government; Tony Blair is quoted describing dealing with Charles as “toxic”, while the prince allegedly “screamed” at David Cameron in 2010, over the then London mayor Boris Johnson’s call to hand over control of the royal parks to the Greater London Authority. Bower writes: “‘Boris is taking over the royal parks?’ he screamed. ‘Why have you given the royal parks to Boris?’ ‘The queen agreed,’ replied Cameron. ‘What? Mama down the road? What does she know about the royal parks?’”

Rebel Prince also tackles Charles’ relationship with his sons, with Bower claiming that he is concerned that the public is more interested in Prince William and Kate Middleton than himself, as well as fretting over his future portrait on coins when he becomes Charles III. According to Bower, Charles was concerned that the original portrait “showed his thinning hair and reflected his age” and “demanded that he should be shown with a full head of hair, and considerably younger. The revised version was more satisfactory.”

“He was less pleased when the Mint suggested that it should also prepare portraits for King William,” writes Bower. “That, Charles ordained, was pushing fate too far.”

Describing himself as a committed monarchist, Bower nonetheless concludes that the prince’s legacy has been “tarnished by his addiction to luxury, his financial mismanagement, his disloyalty to professional supporters, and the torrid relationships with his family”. He expresses concern that Charles, when king, “will act alone, without any restraining adviser. For committed monarchists, that independence is alarming. They can only hope for the best.”

Clarence House has stated that no comment will be issued on the allegations made in the book.