Former Whitehall adviser Patrick Rock has been bailed to appear at Westminster Magistrates Court on July 3 after he was charged over child abuse images.
Judith Reed, a senior lawyer with the CPS Organised Crime Division, said: "We have determined that there is sufficient evidence for a realistic prospect of conviction and that a prosecution is in the public interest."
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The former reality TV star will follow in the footsteps of Abraham Lincoln and John F Kennedy when he takes his oath later on Friday.
The President-elect's comments on Twitter will come under even closer scrutiny when he takes office on Friday.
Cold, quiet and calm