The bands will be joined by Michael Kiwanuka for the latest 'Albums of the Year' nominees live performance at LSO St Luke's in London on October 24.
Fans can enter themselves into a free ballot for the show from 10am on October 15 and have 48 hours to apply.
Successful applicants will be asked to donate £10 for each pair of tickets, with the money given to War Child. Barclaycard will match all donations that have been made using one of their debit or credit cards.
This year's Mercury Prize will be awarded on November 1 and televised on Channel 4.
> Plan B, Jessie Ware, Alt-J among Mercury Prize 2012 nominations
Watch the music video for The Maccabees' 'Ayla' below: