Pop star Lily Allen has been drafted in to support Coldplay at the band's third annual Under 1 Roof concert to help raise funds for a U.K. children's charity. The rockers first curated a concert for the Kids Company in 2011, and now the show is in its third year, they have asked Allen to continue her pop comeback by performing at the gig at the Eventim Apollo in London on 19 December (13). The gig will also feature comedy in the form of David Brent - Ricky Gervais' TV alter-ego from The Office. Gervais embarked on a series of sold out shows as his comedy creation earlier this year (13). Coldplay frontman Chris Martin says, "Buying a ticket to this concert will guarantee two things: a totally unique never-to-be-repeated night of star-spangled entertainment, and money in the Christmas coffers of a charity that brings love and happiness to London's most vulnerable kids." Rizzle Kicks will also perform at the event, which will raise funds to help disadvantaged youngsters in the U.K. capital and Bristol, England. Allen made her official stage return at Robbie Williams' concert at the London Palladium last week (08Nov13).