Christina Aguilera has it out for Tony Lucca on "The Voice" because he spurned her while they worked on The Mickey Mouse Club -- this according to a former Mouseketeer.

Ex-Mouse Clubber Dale Godboldo -- who starred on the 90s MMC revival alongside Aguilera and Lucca -- tells TMZ, Tony was pretty popular in his Disney days ... "Britney was in love with him. Christina was in love with him. Mylin was in love with him."

But Christina and Tony never hit it off -- and Dale believes she's carried a grudge ever since, claiming, "All of this [Voice] madness was not brought on by Tony."

You'll recall ... Aguilera harshly criticized Tony's "Voice" performance Monday night -- calling the rendition of "99 Problems" "derogatory to women." The two have been butting heads all season.

Hell hath no fury like a Mouseketeer scorned.