One of Prince Harry's major demands for when he and his family return to the United Kingdom has been met. 

The Mirror reported that despite his ongoing security dispute with the Home Office, the Duke of Sussex has been offered "cast-iron guarantees" that he, Meghan Markle, and their two children, Lilibet and Archie, would be safe when they arrive in Britain to mark Queen Elizabeth II's Platinum Jubilee. 

The former senior royals are thought to be traveling with only a tiny security crew and without any of their top advisors. According to people with firsthand knowledge of the Sussexes' vacation arrangements, they left their trusty crew in California.

"He has been in frequent communication with the necessary people and made it very plain that he would not fly until he received ironclad assurances for the safety of his family," the person added. 

"He is certain that the proper protocols are in place, and they are all looking forward to this week's celebrations and, of course, spending time with Her Majesty." 

Apart from the Queen's Jubilee, Lilibet Diana will turn one year old this weekend. 

Prince Harry and Meghan Markle will reside at Frogmore Cottage, their previous Windsor home, with their children. 

After leaving their royal jobs in 2020, the former "Suits" actress will only be returning to her husband's homeland for the second time. 

READ ALSO: Prince Harry, Meghan Markle Returning to the UK for Good? Couple Did Unexpected Move

The Mirror also alleged that the Met Royalty and Specialist Protection unit of the UK police spent weeks coordinating with Prince Harry's staff to ensure they had taxpayer-funded security. 

This comes after Prince William's 37-year-old younger brother filed a lawsuit against the UK Home Office when they were denied armed police protection. 

Prince Harry argues that the existing security measures do not make him feel safe and secure, hence he is hesitant to bring his family there. He did, however, offer to cover the cost of their British police bodyguards. 

However, officials informed The Mirror that despite the police assuring that their personnel are not "guns for hire," the father-of-two has always preferred returning to the UK for Queen Elizabeth II's Platinum Jubilee festivities

Meanwhile, the Duke and Duchess of Sussex's California residence in Montecito is reportedly guarded 24 hours a day by a squad of 12 former special forces men.

READ MORE: Why Queen Elizabeth's Platinum Jubilee Is 'Tarnished,' and Not Due to Her Health