The Duke of York and the wife of the foreign secretary are among a select group who will abseil down the Shard on Monday 3 September to raise funds for The Outward Bound Trust and the Royal Marines Charitable Trust Fund.
Local residents have become familiar with the sight of window-cleaners abseiling down the tallest building in Western Europe, but for the first time the opportunity to make the descent has been made available to the public at large.
The Duke of York, who last week took part in the inauguration of the landmark tower at London Bridge, will return to the building for September's fundraising event.
"I am delighted to be leading the Descent of the Shard," said the Duke.
"I am also very proud, as the chairman of The Outward Bound Trust, of the work the trust undertakes with young people to give them challenge through adventure.
"The Royal Marines are also close to my heart as a part of the Royal Navy and whilst the work they do in support of our nation is beyond any question; I am delighted to be joining with the Royal Marines and their Benevolent Trust to be able to raise not only awareness for the two charitable organisations we are descending the Shard for but also in raising the necessary money and support for both organisations to be able to continue our vital work."
So far the Duke's biggest sponsor is his daughter Princess Eugenie who has pledged £500.
Ffion Hague, who is deputy chairman of The Outward Bound Trust, added: "I am excited and proud to be descending the Shard to raise money so that more young people than ever before can benefit."
Places to take part in the event are still available, subject to a minimum sponsorship or donation requirement of £25,000.