Win or lose in Saturday's X factor final, Alexandra Burke is on course to become Britain's next big pop star.

The 20-year-old from Islington is favourite to win, but even if she loses out to rivals Eoghan Quigg or JLS, industry sources say its "only a matter of time" before the show's impresario Simon Cowell gets her in the studio working on her debut album.

Destined for great things: Alexandra

Senior executives at Sony BMG, the label which signs up the finalists, believe Burke has the potential to be as successful as Leona Lewis, who won the show two years ago and has now sold more albums that any debut artist.

One record industry source said: "There's talk of her spending a few months in the US with some of the producers who worked with Leona, but I've heard they may look to have a more 'British' sound for Alexandra in keeping with her mum's background with Soul II Soul."

Alexandra, who sang in the choir of the Elizabeth Garret Anderson School in Barnsbury, has won praise from soul stars Beverley Knight, Gabrielle, and Joss Stone whom she sang with aged 12 on the TV show Star For A Night. In last week's semi-final, her rendition of Toni Braxton's Unbreak My Heart prompted a standing ovation from the four judges. She will see her "dream come true" by singing with Beyoncé on Saturday.

If she wins, Alexandra will release a cover version of the Leonard Cohen song Hallelujah, a song which could claim the Christmas No 1 slot.

Her 44-year-old mother, ex Soul II Soul singer Melissa Bell missed the semi-final due to kidney failure brought on by diabetes, but has vowed to be there for the final. The mother-of-four is on the waiting list for a transplant and has three bouts of dialysis each week. Alexandra said: "Mum won't let me donate a kidney. Diabetes has killed every woman in my family - and it is triggered by having kids. If I donate a kidney I couldn't have a baby as I would only have one kidney left to fight the disease."

Alexandra applied for X Factor in 2005 and narrowly missed out on making the live shows. She vowed not to audition again, but the loss of a close family friend changed her mind.

Pauline Harty, who cared for Alexandra, her sister and two brothers while their mother was touring, died of lung cancer in March. She had wanted Alex-