Louisa Johnson and Reggie 'N' Bollie battle it out in X Factor final

Louisa Johnson and Reggie 'N' Bollie will battle it out for the X Factor crown on Sunday night.

Seventeen-year-old Johnson is the bookies' favourite to win, which would make her the youngest X Factor victor in the show's history.

Ghanaian rap duo Reggie 'N' Bollie have consistently surprised the judges by dominating the public vote but will have to pull out a spectacular performance to pip the Essex frontrunner to the prize record deal.

If Johnson prevails, she will become the first winning act for mentor Rita Ora, who jumped ship from BBC show The Voice this year, while Reggie 'N' Bollie would become Cheryl Fernandez-Versini's third winning act after Alexandra Burke and Joe McElderry.

The two acts will perform their winner's song live on the results show, giving viewers a taste of the track they might be hearing at number one this Christmas.

The grand final show will include a performance from Adele, who will be taking to the show's stage to sing record-breaking hit Hello which she first teased in a 30-second snippet during an X Factor advert break.

One Direction, who were formed on the show in 2010, will return to perform track Infinity from their new album Made in the AM, their last before the band take a break from March 2016 onwards.

Completing the guest line-up are Coldplay who will be performing Adventure of A Lifetime from their new album A Head Full Of Dreams.

Che Chesterman, 19, who was mentored by Nick Grimshaw, received the fewest public votes on Saturday night and was voted off in third place.

:: The X Factor will air at 8pm on ITV.