Paloma Faith, Jamie Cullum, KT Tunstall, James Morrison and Biffy Clyro are among the stars performing at a surprise free show in London as part of a protest movement ahead of the upcoming G8 conference.

A host of artists agreed to take part in the ONE Campaign's pop-up show outside the British capital's Tate Modern art gallery on Wednesday afternoon (12Jun13) to sing protest songs as part of the organisation's week-long anti-poverty Agit8 drive.

Cullum covered High & Dry by Radiohead, while Paloma Faith sang a track by Bob Marley.

Other artists expected to take part in the show later on Wednesday include Newton Faulkner, David Gray and Tom Odell, while Jessie J, Tinie Tempah, Jake Bugg, Jools Holland and Sir Tom Jones are rumoured to be among the line-up scheduled for Thursday's (13Jun13) gig.

Other events planned at the site include the screening of a special short film by director Richard Curtis which will be projected onto the side of the iconic Tate Modern building.

Demonstrations kicked off in the U.K. capital on Tuesday ahead of this month's (Jun13) gathering of world leaders at the G8 Summit in Northern Ireland, and Agit8 performer Tunstall was given an up-close glimpse of the trouble as riot police and protesters engaged in a stand-off outside the radio station where she was recording an appearance.