Aguilera's mouth tied shut in political advert

Christina Aguilera is getting political in a harrowing new advert for America's Declare Yourself pro-voting campaign.

The pretty pop superstar is seen weeping while her mouth is tied shut with satin string in the hard-hitting images taken by Dirrty video maker David Lachapelle.

Ben Affleck recently appeared in TV ads for the Declare Yourself campaign, playing a pedicurist to a demanding German woman.

Aguilera's new ads will appear in style magazines throughout August and September.