The coaches from The Voice will team up to form a supergroup in Saturday’s final, which sees the show’s four remaining singers compete for a coveted record contract.

The quartet will perform a medley of their own hits in the two-hour special, during which either Vince Kidd, Bo Bruce, Tyler James or Leanne Mitchell will be crowned series winner.

Bo – who is representing Danny O’Donoghue’s team – is the current favourite to take the prize, following the surprise exit of favourites Jaz Ellington and Ruth Brown in last weekend’s semi-final.

Each of the four finalists will also perform with their mentor during the show, while there will also be guest appearances from Maroon 5 and Ed Sheeran.

The series was initially popular with viewers, averaging audiences of over 10m in its early ‘blind’ audition stages, and beating Britain’s Got Talent in the ratings three weeks in a row.

However viewing figures have dropped by over half during the recent live finals, with just 4.5m tuning in to last weekend’s show despite appearances from Cheryl Cole and Kylie Minogue.

TV bosses have said that the format needs a shake-up next series to maintain viewer interest, with reports in the Mirror that all four judges could face the axe – but the show will return next year despite the disappointing figures.

“We’ve already paid £22m for two years so there is no question of it being axed,” a BBC source told the paper.

“But it seems unlikely any of the current coaches will be back. The audience haven’t connected with them.

“The show got off to a fantastic start, but the fans got bored of the same ultra-positive comments every week, and so the viewing figures tumbled.”

The final kicks off on BBC One at 7.20pm.