The King and Prince Harry have had a strained relationship in recent years - Max Mumby/Getty

Team Sussex is understood to be frustrated after details of a “peace summit” were revealed in a newspaper, denying it was behind the leak.

Senior aides working for the King and Prince Harry took the first steps towards rapprochement by holding sensitive talks last week.

The meeting, at a private members’ club in central London, was an extraordinary development in relations between the two Royal households, which have been almost non-existent in recent years.

Details including the venue, timings and nature of the talks were leaked to the Mail on Sunday. This led to the aides being “papped” outside the club and even during the meeting as they enjoyed drinks on a balcony.

The leak has jeopardised the fragile peace operation, creating further suspicion and distrust on both sides and potentially sending them back to square one.

Sources close to Prince Harry insisted that the Sussexes were not responsible, and acknowledged that having the details of the meeting on newspaper front pages was hardly an ideal way to start what they had hoped would be a new period of peace.

Buckingham Palace declined to comment.

Tobyn Andreae, the King’s communications secretary, was present at the summit - Max Mumby/Indigo/Getty

Meredith Maines, the Duke’s new chief communications officer, based in California, was joined at the meeting by Liam Maguire, who runs the Sussexes’ UK-based PR operation, and Tobyn Andreae, the King’s communications secretary.

The meeting was orchestrated in a bid to start afresh, with both sides recognising that an open communications channel would benefit them all.

A source told the Mail on Sunday: “There’s a long road ahead, but a channel of communication is now open for the first time in years. There was no formal agenda, just casual drinks. There were things both sides wanted to talk about.”

The meeting came weeks after the Duke told the BBC that he wanted to “get my father and brother back”. It was hoped that the summit, at the Royal Over-Seas League near Clarence House, would be a line in the sand.

Ms Maines and Mr Maguire arrived at the meeting by taxi on Wednesday afternoon, followed by Mr Andreae. The trio were seen on the club’s first-floor garden terrace before moving inside.

The source described the summit as the “first step towards reconciliation between Harry and his father” and a “a step in the right direction”, adding: “It was finally the right time for the two sides to talk.”

Liam McGuire (top left), who runs the Sussexes’ UK PR operations, pictured at the 2018 Invictus Games with the Duke and Duchess - Chris Jackson/Getty

The feud began when the Sussexes left their royal duties and moved to America amid furious negotiations over the terms of their “exit deal”.

Since leaving for the US, the Sussexes have shared intimate family revelations and made damaging allegations in a series of television interviews as well as in Spare, Prince Harry’s memoir.

Senior royals became “wary” of talking to the Sussexes for fear their words would be repeated in public.

The rift widened significantly following the Sussexes’ 2021 interview with Oprah Winfrey, during which they alleged that a member of the Royal family was concerned about their son Archie’s skin tone before he was born.

Then the Duke claimed in his controversial memoir that his brother had physically attacked him and that the King put his own interests above Harry’s and was jealous of Meghan.

Prince William, in particular, was angry about how the Princess of Wales had been portrayed and at his brother’s betrayal for commercial gain.

Greatest Interviews

Prince Harry speaks to Briony Gordon in Montecito

When it was announced that the King had been diagnosed with cancer in February last year, Prince Harry made a transatlantic dash to see him.

But the Duke’s decision to take on the Government in the High Court over his access to state-funded police protection deepened the rift.

The Duke believed the King could intervene on his behalf to negotiate an arrangement, but the King was said to have been so worried about being dragged into the case that he was hesitant to engage with his younger son in case his words were repeated in public. Harry lost his appeal in May.

The 2027 Invictus Games in Birmingham is one opportunity for a public reconciliation being discussed by both sides. The Duke is said to have sent email invitations to Buckingham Palace in the hope that it will give the King sufficient time to fit the event into his busy schedule.

The prospect of the monarch’s attendance is understood to have been discussed by senior palace aides, aware that the Games could prove a timely opportunity to mend bridges.

Sign up to the Front Page newsletter for free: Your essential guide to the day's agenda from The Telegraph - direct to your inbox seven days a week.