Contostavlos, of St Albans, Hertfordshire, stood in the dock in a white shirt, black trousers and black trainers as the charge was read to him.
He was granted unconditional bail and will stand trial at Chelmsford Magistrates' Court on June 18.
The former N-Dubz singer finished in second place on reality show Celebrity Big Brother in January.
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A protest march has been held in Huntingdon over plans to merge two local hospitals to save money.
A protest march has taken place in Huntingdon over plans which could see Hinchingbrooke Hospital merge with Peterborough City Hospital