A six-minute clip of Tulisa and ex-boyfriend Justin Edwards was leaked onto the web last week, featuring the pair having an "intimate moment" backstage at a gig.
The star's step mum yesterday blasted the N-Dubz star in an interview with The People.
"I'm appalled. The fact that she would even allow a tape like this just shows she doesn't respect herself," Melanie Vondrau told the newspaper. "A young girl who respects herself would choose her partner very wisely. She is clearly not making the right choices."
Melanie, who divorced from Tulisa's dad in 2009 after a 10-year relationship, said the 23-year-old couldn't afford to have incidents like the tape ruin her career.
She said: "She is so talented and has the chance to make it big.
"She can't afford for stuff to come out like this. She needs strong loving parental guidance."
Melanie added: "Unfortunately for Tulisa her mum is not very well and she has got a father who is a distant character."
Tulisa will appear at the High Court today represented by her legal team in a bid to get an injunction on the tape extended.
The video was originally being sold for £3.60, or $5.99, on an adult website.