Pop star Katy Perry is set to stage a free concert in Milwaukee, Wisconsin this weekend (03Nov12) to help rally last-minute support for incumbent President Barack Obama ahead of the elections on Tuesday (06Nov12).

The I Kissed A Girl hitmaker has become one of the politician's biggest celebrity supporters as he fights for a second term at the White House and she recently performed at a fundraising event in Los Angeles and at a campaign rally in Las Vegas last month (Oct12), when she wore a white latex dress designed to look like ballot paper.

The singer has now signed up to play her third pro-Obama gig in the swing state of Wisconsin on Saturday. She'll appear alongside the leader as part of a campaign to energise young citizens in the run-up to the big day.

Perry isn't the only famous face putting in extra work ahead of the elections - actress Eva Longoria and singers Stevie Wonder, Marc Anthony and Dave Matthews are all due to appear at Democratic events in the next few days.