An X Factor spokesperson yesterday confirmed 39-year-old Mel is 'still unwell and at this stage we don't know if she will be able to do the final."
Sources revealed that head judge SImon Cowell, 55, asked Tulisa to step in, telling the Mirror: "Tulisa is really happy to help out.
"She knows how important it is for the contestants to have someone there for them, and getting behind them, especially when it is so near to the final.
"She will be making sure that Andrea gets as much help and guidance as possible."
It is still unclear what exactly is wrong with former Spice Gil Mel, but last night she was rushed to hospital to undergo tests.
An insider said: "She is in hospital and is seriously ill. We are awaiting the result of tests and then we will know exactly what is wrong.
"If I had to predict, having seen her, I don't think she will be able to do the show. Miracles do happen and the doctors may say she is well enough to leave but, looking at her, I would be amazed if that happens."
Andrea, 20, was overheard at rehearsals saying: "I feel abandoned". It is thought he hasn't heard from Mel since Tuesday.