Alisa Apps has challenged Lady Gaga to a live, televised sing-off and called her 'a plastic doll.'

The little known L.A. singer wants it to take place in either New York's Madison Square Garden or London's O2 Arena with the winner taking home a cash prize of $1 million.

Alisa denies that the challenge is a way of raising her profile, instead claiming she is doing it out for pity for Lady Gaga:

"I feel sorry for Lady Gaga â€" she's just a plastic doll generated by the music money marketing machine. I stand for the voice of your heart. Be real with me.

"Come to my world and feel. I want to hear you and for you to hear me. This contest gives people a chance to choose which they prefer: plastic or real."

There has been no comment from Lady Gaga as to whether she has any interest in the challenge.