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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Ukip has responded to the resignation of its only MP, Douglas Carswell, by suggesting he quit before he was kicked out.
A mostly warm afternoon but a fresh easterly breeze will bring a noticeably cooler feel along eastern coasts. Highs of 15 deg C (59 deg F).
ITV News Anglia's Political Correspondent Emma Hutchinson asks what next for UKIP after Douglas Carswell quits the party?