91�ȱ�

Jessie J has responded to critics who said her performance on last week's X Factor was out of tune.

The singer said: "I was on X Factor on Sunday. Afterwards I went on Twitter, and so many people were attacking me because I was pitchy.

"It [the performance] was out of tune, but I've never mimed and I'm proud of that."

The 23-year-old, whose real name is Jessica Cornish, was speaking at 91�ȱ� Radio 1Xtra Live in Brixton.

She added: "I would never surround myself with people who tell me I'm perfect because I'm not and I don't want to be.

"I'm 23, and sometimes I sing out of tune. Sometimes I say stuff that I shouldn't and sometimes I'm going to make mistakes."

Jessie J made the comments before performing her current single, Who You Are.

She said: "This next song, I hope it is in tune because that's the way it's supposed to be sung.

You can watch Jessie J's 1xtra Live performance here.

Jessie J topped the 91�ȱ�'s Sound of 2011 poll in January, beating James Blake and The Vaccines to the title.

In February, she topped the UK singles chart with Price Tag, a collaboration with B.o.B.

The singer has also had top 20 hits with Do It Like A Dude, Nobody's Perfect and Who's Laughing Now.

Last month Jessie J was the first coach to be announced for The Voice UK.

The 91�ȱ� One show is due to be broadcast in spring 2012.

She will be joined on the coaching panel by Black Eyed Peas singer will.i.am.