Nicole Scherzinger has admitted that she had no idea who British Prime Minister David Cameron was when she met him recently.

The X Factor judge was introduced to the PM at the Mirror Pride of Britain Awards on Monday (October 29) - but she still thought former Labour leader Tony Blair was in charge.

Speaking to the newspaper about the faux pas, the singer said she was a "real ass" over the embarrassing incident and had to be told who she just met was.

Recalling what it was like to meet the current Prime Minister, Scherzinger said:

"Who's David Cameron? Oh, the Prime Minister."

She continued: "I didn't know who he was. They said they were introducing me to the Prime Minister and he came over, and I was like: 'Where's Tony Blair?' I thought it was still him. Someone had to tell me. I was a real ass."