The Sun reports that their legal team will argue that there was "procedural unfairness" when the security arrangements outlined in a letter from Ravec and their application when Harry visited England in June 2021 was deemed invalid.
Shaeed Fatima QC, who was representing the prince in court, also shared: "He didn't know at that stage that the Royal Household was involved at all... he was told it was an independent decision."
She also stressed that written arguments given to Harry from the Royal Household were not "clear and full explanation" of Ravec and those involved in making the decision.
The duke maintains that his security concerns passed onto the royal staff were "fully and properly communicated to Ravec."
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Shaeed argued that Harry was barred from making direct representations to Ravec, and he was "materially prejudiced" because "among other things, his offer to pay (for security) was not conveyed to Ravec before the decision was made".
"He does not know what else - as communicated by him to the Royal Household - was not fully conveyed to Ravec," she communicated.
"He was deprived of the opportunity to comment on the appropriateness of Ravec's process (and) the involvement of certain individuals in the Ravec process prior to the decision being made.
"It is arguable that, if there had been a fair process, Ravec would or could have reached a different decision."
The 37-year-olds' legal team also hinted he could proceed with a second lawsuit in the court filing.
"[Prince Harry] has engaged in pre-action correspondence for a proposed second judicial review claim in relation to these matters, and intends to issue that claim shortly," it read.
The document also details: "Prince Harry's offer (to pay for police protection) was made at a meeting on 13 January 2020 at which members of TRH [The Royal Household] were present and is also referred to in an email to Sir Edward Young of 16 April 2020.
"There has been no explanation of why the offer was not conveyed."
The Home Office's lawyers maintain they were entitled to their decision, and they considered Harry's application on a "case by case" basis.
Sir James told the court: "[There was] no basis for the court to conclude that it would be anything other than highly likely" that allowing Harry to make representations to Ravec before the decision was made "would not have led to that decision being substantially different, or even at all different".
The royal employee representing the Home Office also argued that the tensions between Harry and the household were "irrelevant" regarding his status change.
"In his skeleton, the claimant now refers to objections he might have made to any role being played by officials of the Royal Household in Ravec's decision-making - apparently because of personal tensions he felt with them," he said.
"But there is no bias challenge and any such tensions are irrelevant to the undisputed fact of the claimant's change in status which led to the decision of Ravec.
"The inability of the claimant even now to explain how a process of representations could or would have assisted is striking."
This article originally appeared on our sister site, Now To Love.