John Mayer has poked fun at Australian Britney Spears fans who were “shocked” to discover that the singer mimes on her Circus tour.

The Womaniser star has been slammed by supporters and critics alike for lip-synching through her recent 'live' shows in Perth.

Which begs the question: what were they expecting?

As Mayer Tweeted over the weekend:  "If you're shocked that Britney was lip-syncing at her concert and want your money back, life may continue to be hard for you."
 
The furore has even prompted politicians in Western Australia, Victoria and New South Wales to call for legislation that would force promoters to disclose whether or not an artist will be singing live.

Roll up! It's Britney's Circus