Through his success in the task, his fellow housemates will now receive a luxury food hamper.
Called to the Diary Room, Big Brother told Harry he would have to prove that he was over 90% posh.
The "150% Conservative" entrepreneur gained 'posh points' for tying three sailor knots, revealing that he met Prince Charles at a Polo match, and speaking candidly about how he would woo Pippa Middleton.
However, he was unable to tie a bow tie in less than 90 seconds, and wrongly identified a sherry glass as a port glass.
Nevertheless, Big Brother gave Harry an overall score of 93%.
After failing Tuesday's Stranded task, tensions rose in the house after contestants had to settle for an economy shopping budget.
These Big Brother scenes will air tomorrow night from 10.55pm on Channel 5.
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