The 'Live it Up' singer picked the pair when speaking to Little Mix member Jade Thirlwall on The Xtra Factor.
Thirlwall pointed out that her own band had been far from favourites in week one of their series, and asked Contostavlos who she thought might be the dark horses this time.
Louis Walsh butted in, saying he was going for Jahmene Douglas.
After Consostavlos pointed out that Douglas was already a "strong contender", she went for duo Lotte Rundle and Simeon Dixon.
Earlier in the evening, MK1 had been praised by the judges for their performance of 'Champion'/'Everyone's a Winner'.
Copyright: Ken McKay/Thames/Rex Features
When MK1 were asked on The Xtra Factor whether they thought they could go further with Contostavlos as their mentor rather than Walsh, Dixon insisted: "I think Tulisa would do a really, really good job. However Louis is, like, experienced, and the way he understood when we went for that 'Champion' song as well, he just clicked and knew it would work for us, so I don't think it would be an issue having Tulisa or Louis."
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