The boy band appeared on the first episode of this year's auditions singing a track from Les Mis and have been tipped to win ever since.
Collabro remain the strong favourites with Ladbroeks at 5/1, or there's 7/1 on offer for the first golden buzzer act Paddy and Nico to be crowned the champions of 2014.
From the weekend's latest audition show, it's Jack Pack who are already being heavily backed by punters for Britain's Got Talent glory.
The swing group have swung towards the top of the betting and the bookies make them a 10/1 chance to win this year's talent show, however despite having a place already in the live shows after getting Alesha Dixon's golden buzzer, REAformed are amongst the outsiders at 25/1.
Meanwhile the third of the current golden buzzer acts, Christian Spridon, is given odds of 100/1.
Jessica Bridge of Ladbrokes said: "Although Jack Pack impressed the judges and punters alike, we're not sure they're up to Collabro's level of popularity yet and that's reflected in the odds."
Britain's Got Talent winner 2014
Odds from Ladbrokes
7/1 Paddy and Nico
9/1 Lucy Kay
10/1 Darcy Oake
10/1 Micky Dumoulin
10/1 Kings and Queens
10/1 Jack Pack
12/1 Light Balance
12/1 Bailey McConnell
14/1 James Smith
14/1 Kieran Lai
20/1 Andrew Derbyshire
25/1 Christian Farla