The Duke of York will abseil down the Shard skyscraper in London for charity today.
Other participants include Ffion Hague, the wife of Foreign Secretary William Hague, and leading businessmen and women.
The Shard is the tallest building in Europe, and its viewing galleries will be open to the public in February next year.
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It will be a misty and cloudy start in many southern and central parts which will slowly lift this morning.
The president-elect also warned US companies they would face "retribution" for setting up their business operations abroad.
Penalties of £100 or a court fine of up to £1,000 can now be handed to anyone caught lighting up in a private vehicle with someone under 18.