The outlawed group has said the singer from Assam, Debojit Saha, should make his stand clear on the promotion of Hindi music in the state - something the ULFA is dead against.
The show aired on Zee TV every Thursday and Friday has reached a climax with Debojit among the top two. Although results are expected to be formally announced Friday.
Only one more performance is left to clinch the "Voice of India" title.
"We respect Debojit's musical talent. But is the hype and support for Debojit justified, as we ought to know if he has really helped promote the cause of the state's folk music through 'Sa Re Ga Ma Pa'?" ULFA said in a statement Thursday in its mouthpiece Swadhinata.
"We are not going to tolerate the promotion of Hindi music in our state. It is time Debojit made his stand clear," the rebel statement added.
The format of the show is such that one contestant gets eliminated on the basis of the least number of votes received on SMS or phones after performances aired each week.
Debojit in the past few shows has been the leader, polling the highest number of votes - the bulk of which is from Assam and other northeastern states, thereby triggering a debate among the musical mentors in the show about its format.
Earlier there were reports from Mumbai alleging that ULFA had threatened brand manager of the show on ZEE TV to ensure that Debojit was not eliminated. But the rebel group denied the charges in the statement, saying it would never indulge in things that had no relevance in Assam.
The journey for Debojit has indeed been remarkable - from being one of 32 contestants to reaching the final two, the musical juggernaut is rolling very well for this young engineer from southern Assam's Silchar town, about 300 km from the state's main city of Guwahati.
Debojit has no doubt been hitting the high octaves perfectly in the singing contest, but like in any elections one requires a fair amount of extra skills to translate those performances into votes.
The Debojit fan club has plastered almost every nook and corner of the northeast with posters and banners urging people to vote for him through SMS or land phones. They are running media campaigns, besides roping in influential groups to back him.