Katy Perry is offering fans the chance to appear alongside her in a CoverGirl commercial.

The 'Dark Horse' hitmaker took to her Twitter account last night (29.07.15) to reveal fans will be able to appear in the latest advert for the cosmetics' brand's Super Sizer mascara.

She wrote: ''Wanna [star emoji] in ur own #COVERGIRL commercial to air during #VMA's? Let's advertise your eyes! (sic).''

Katy also included a link to a page on the CoverGirl website where budding models and fans of the star can upload images of themselves wearing the eyelash plumping product.

The page reads: ''Supersize yourself #Lashfame Star in a video with Katy Perry and the Super Sizer mascara

''Upload a picture of yourself and your super-sized lashes with #lashfame for a chance to be featured in a commercial during the MTV Video Music Awards. Scroll first to create your video with Katy. Then, register your creation for a chance to win.''

The 30-year-old beauty was first unveiled as the new face of CoverGirl earlier this year, although she previously appeared in ads for the brand in 2013.

Following the announcement, Katy said: ''In addition to music, I've always considered make-up to be a powerful creative avenue for self-expression for me.''