Security sources said the abrupt changes to the Duke of York’s status following the removal of his military titles as well as him relinquishing the use of his “HRH” styling will trigger a review of his requirements by the secretive government committee in charge of deciding royal protection deployment.

The Royal and VIP Executive Committee (RAVEC), which brings together representatives from the Metropolitan Police, the Home Office, Buckingham Palace and, where appropriate, the security services, meets regularly to consider the level of protection needed for senior royals.

A UK Government minister yesterday declined to comment when asked whether the prince would continue to receive publicly-funded security, provided by Scotland Yard’s elite Royalty and Specialist Protection Command, on the basis that such requirements are not publicly disclosed.

Prince Andrew is being sued in a court in the US over alleged sexual abuse. Picture: Tristan Fewings/Getty Images

Security minister Damian Hinds told LBC radio: “Our security forces, the police and others, do what they judge is necessary to protect our country, to protect people in it.”

He added that it was a “long-standing – and I think correct – principle that we don’t talk about who and how in particular”.

The annual cost of guarding the royal family is estimated to be in excess of £100 million.

It is understood that elements of the duke’s taxpayer-funded protection could continue despite Thursday evening’s dramatic announcement that he will be conducting his future activities – chiefly fighting the sexual assault claims being brought against him by Virginia Giuffre, a victim of paedophile financier Jeffrey Epstein – as a private citizen.

A security source said: “The RAVEC rules are not one size fits all – a lot depends on the assessment of the threat level faced by individuals.

"Prince Andrew may not be in the immediate line of succession, but he remains significantly in the public eye because of the ongoing legal case and that is a factor which would be considered.

"[Police] protection is only removed when a threat level is considered low enough and that is something which would be looked at whenever there is a significant change in circumstances.”

Dai Davies, a retired Yard chief superintendent previously in charge of royal protection, said: “I think [the Metropolitan Police] will be very cautious until there has been a very thorough assessment and [Prince Andrew] will remain protected at least in the short term. There are very strong feelings about him at the moment ... so that threat is there.”

The duke’s home, Royal Lodge on the Windsor estate, on which Andrew spent some £7.5m to fund renovations including a swimming pool, will remain under police protection because of its proximity to Windsor Castle and wider security provision for the Queen and other royals.

It is understood that arrangement is unlikely to change even if the duke and his former wife, Sarah Ferguson, with whom he shares Royal Lodge, eventually move to a smaller residence such as nearby Frogmore Cottage, previously the home of the Duke and Duchess of Sussex until their decision to step back as working royals and move to California.

Prince Andrew is no stranger to debates over the source of funding for his family’s security arrangements.

The financing of police protection for his daughters, Princess Beatrice and Princess Eugenie, has previously caused difficulties, in particular the provision of a police bodyguard at a cost of £250,000 a year while Eugenie attended Newcastle University.

The princesses lost their publicly-funded protection in 2011, leaving it to the duke and his wife to pay for security from private sources.

At least one of those sources is likely to be funding the Queen provides to minor royals from her personal sources of income, including that received from the Duchy of Lancaster.

The security source said: “It is not unheard of for there to be a hybrid arrangement by which some protection costs are met from the public purse and others are covered privately. That may well be where things end up with Andrew.”

Graham Smith, chief executive officer of the organisation Republic, had earlier called on the Queen’s second son to foot the bill for his police protection as there was no prospect of him returning to royal duties.

Mr Smith, whose organisation campaigns for an elected head of state, said about the royal family: “Why should we be paying for their security?

"The job of the monarchy is to give us one head of state – we don’t need to be giving security to all of them. Lots of celebrities and other high-profile people pay for their own security.

“Given that he’s no longer in any real sense a member of the royal household it does make sense he pays for his own security.”

Rachael Maskell, Labour MP for York Central, tweeted it was “untenable” for Andrew to cling on to his title “another day longer”.

Andrew’s dramatic fall in the standing of the royal family came after Virginia Giuffre’s lawsuit against him took a major step forward on Wednesday when a judge threw out a motion by the duke’s lawyers to dismiss the sexual assault case and ruled it can go to trial.

The duke has strenuously denied the allegations.

Prince Andrew could retain public-funded security despite being stripped of royal titles by Queen