A jury at Blackfriars Crown Court, in central London, was told that the 28-year-old and his business partner snorted the drug through a pounds 5 note in a suite at the Savoy Hotel, unaware that they were being recorded after being "set-up" by a tabloid newspaper. The earl allegedly said: "Come on, bring on the charlie. I want a big fat line. I am going to have the biggest line I have ever had in my life and then be sick."
A day later, the court was told, the earl took the man he believed to be "Sheikh Mohammed" and one of his make-believe aides on a hospitality tour of the House of Lords before meeting the pair in a restaurant to hand over a consignment of the drug.
In 1998, Lord Hardwicke and Stefan Thwaites, 29, of Tooting, south London, were running an Italian motorcycle franchise in Tooting, south London, and their future looked secure. But in early September, after the newspaper "sting" operation, the earl was suspended from the Tory whip and both men were accused of drug dealing.
Martin Hicks, for the prosecution, told the court that on 27 August last year, a man claiming to represent Middle Eastern clients visited the defendants' shop in Tooting, expressing an interest in scooters.
A meting was arranged at the Savoy Hotel, where the two men were introduced to what they took to be two Arab businessmen. It was there that the conversation turned to drugs, said Mr Hicks, and the trap was set.
The earl - charged as Joseph Philip Hardwicke, of Barons Court, west London - pleads not guilty to one count of being concerned in the supply of 2.44g of cocaine to the investigations editor of the News of the World, Mazher Mahmood, on 2 September last year. He also denies supplying 1.49 grams of the drug the following day.
Stefan Thwaites, 29, of Tooting, south London, pleads not guilty to the charge that he actually supplied the 2.44g. He also denies a charge of supplying 1.49g of the drug the following day.
The case continues.