Justin Bieber has explained why he wore dungarees and a baseball cap when meeting the Canadian Prime Minister.

The singer recently picked up a Diamond Jubilee Medal - an award which celebrates achievements abroad - from political leader Stephen Harper.

However, his casual choice of clothing led some online dissenters to call Bieber the "white trash prince" - something which didn't sit too kindly with the pop star.

Taking aim at the Daily Mail's Hayley Peterson, who doesn't appear to have called Bieber "white trash" herself, the singer said on Instagram that he didn't have time to change into smart clothing. The 'Believe' man said:

"The pic of me and the Prime Minister was taken in a room in the arena where i was performing at that day. I walked straight from my meet and greet to him, if you 'Hayley' expect me to have a change of clothes let a loan [of] a suit at that specific time that's crazy, It wasn't like it was like I was going into his environment we were at a hockey arena. Wow am i ever white trash hayley peterson lol."

Watch Bieber and Nicki Minaj's 'Beauty and a Beat' below: