The brothers' former band Oasis had a fierce rivalry with Albarn's group Blur during their heyday in the 1990s but elder Gallagher sibling Noel has since buried the hatchet with the Parklife singer.
The pair cemented their friendship on Saturday (23Mar13) by taking to the stage together during the 2013 Teenage Cancer Trust charity shows in London, which Noel curated, but the event has infuriated Liam.
The singer, now frontman of Beady Eye, has slammed his brother's performance at the show and made reference to a previous controversy when Noel attended a Downing Street reception in 1997, hosted by then-Prime Minister Tony Blair.
In a post on Twitter.com, Liam writes, "Don't know what's worse Rkid (Noel) sipping Champagne with a war criminal or them backing vocals you've just done for Blue (Blur)! Lg."