A "ginger extremist" who fantasised about shooting Prince Charles so Harry could be king has been found guilty of plotting a terror attack "for the Aryan people".

Mark Colborne, 37, likened himself to Norwegian far-right terrorist Anders Breivik and made notes in his diary of his plan to assassinate the royal heir with a high powered sniper rifle.

He bought the ingredients for deadly poison cyanide over the internet, and stockpiled dust masks, metal filter funnels, plastic syringes and latex gloves, jurors were told.

Colborne was caught after his half brother uncovered chemicals and papers detailing his racial hatred stashed in his bedroom at the family home in Southampton.

Following a retrial at the Old Bailey, he was found guilty by a majority of preparing terrorist acts before his arrest on June 3 last year.

The jury convicted him on the basis that Colborne possessed handwritten notes copied from internet sources such as The Terrorist Handbook, The Complete Improvised Kitchen and The Jolly Roger Cookbook about the production of viable explosives.

They also agreed that he had books with titles including Assorted Nasties, Silent Death and The Poor Man's James Bond, which contained recipes for the production and delivery systems of lethal poisons such as cyanide.

However, the jury rejected aspects of the allegations that he intended to use the chemicals and paraphernalia as part of the terror plot.

As Judge John Bevan QC adjourned sentencing to 3 November, he commented that it was a "very strange" case involving a "very strange person".

The court heard Colborne felt alienated and marginalised for being a white, ginger-haired, man and also suffering from agoraphobia and depression.

In his notebook, he wrote: "I don't want to be a serial killer. I'm more of an Anders Breivik. I have left potential targets open.

"I was waiting for an opportunity to kill one of them. Let it be Prince Charles which would be good."

He went on to state that he wanted a "silent rifle", adding: "Take up a good position and put a bullet in Charles's head.

"He is protected but not too protected. I would sacrifice my life for that one shot. Kill Charles and William and Harry become king. Kill the tyrants."

Prosecutor Annabel Darlow QC said Colborne's notes expressed hatred for "non-Aryans" who he referred to as "blacks and Caucasian idiots".

Comparing himself to other right-wing extremists, he wrote: "I'm looking for major retribution, a mass terrorist attack which will bring to the attention our pain not just mine but my brothers around the world."

On June 3 last year, Colborne's half brother Kevin was preparing to do some decorating at the family home in Butts Road when he came across some receipts for chemicals.

He became concerned to learn that they included chemicals that could be used for fireworks and told their mother Patricia what he had found.

Together, they went into Colborne's "extremely cluttered" bedroom and uncovered an assortment of chemicals, the books and other equipment and called the police.

In his defence, Colborne admitted buying the chemicals and writing the diary but dismissed entries as "angry rants" made when he was off medication for depression.

He said: "Fantasies about killing people as a hitman - that was my number one fantasy. Terrorism fantasies were sort of subsidiary but my main interest in being a professional hitman had taken over."

Colborne had faced a retrial after a jury failed to agree a verdict in May.