The 15-year-old that Treasury Board President Tony Clement called a "jack ass" on Twitter said he was "shocked" by the insult.

Clement apologized for offending Keith Pettinger of Parry Sound, Ont., via the social networking site Tuesday.

The gaffe was made Saturday after Pettinger said he responded in jest to a tweet made by Clement.

Clement had said in a Twitter message, "Coach's Corner gave me a lot to think about tonite ..."

Pettinger replied to the tweet by saying "@TonyclementCPC would you like to come to Parry Sound High School on Monday with me and learn how to spell tonight properly?"

He also tweeted, "@TonyclementCPC: Coach's Corner gave me a lot to think about tonite..." Tonight* ...if you can't spell how can you run Canada's treasury?"

Pettinger told CBC News Tuesday that he was shocked when Clement responded by calling him a jackass.

"I was shocked and amazed at first … that he’d do that on a social networking site where the moment you click enter it’s out there forever and anyone can see it," Pettinger said.

"I was really surprised someone so high up in the government would use that kind of language to a fellow countryman and people in their riding, I definitely was surprised that my MP would say that to me."

Pettinger received the apology through a direct message on Twitter Tuesday morning.

"He said he was sorry he offended me and he hoped I’d keep interested in politics," he said.