The PM said he preferred other acts to Jedward
Gordon Brown has said he thinks X Factor's twin contestants John and Edward Grimes are "not very good".
The double act has provoked the ire of many of the viewing public but has been voted into the latter stages of the ITV1 singing contest show.
The prime minister told Manchester radio station Key 103 he did not rate the twins but added that some of the other contestants were "really good".
Mr Brown has declared himself a "fan" of X Factor.
Questioned by an audience of mostly young people in Manchester, the prime minister said : "I don't think they're very good".
He added: "There are some really good people on X Factor. It's really good. And I know it's competing with Strictly Come Dancing".
The question came from teenage actress Brooke Vincent, who plays Sophie Webster in Coronation Street, who was in the audience.
She said to him: "You're like, quite high up there. You're like a top dog, aren't you? So you could like ring in, and say 'we don't want 'em'."
To laughter, the prime minister then asked the audience : "Does anyone want John and Edward to win X Factor?"
Only two said yes.
With their happy singing style, John and Edward - commonly known as Jedward - have divided opinion.
Judge Simon Cowell has said: "If they win, it will be a complete and utter disaster. I'd probably sulk for about six months [and] get on a very fast plane out of the country."
On the show, the twins' progress is being overseen by judge Louis Walsh.