"The labour market testing requirements were introduced by the Rudd government amid claims of "widespread employer rorting". They will require companies to show they have tried to recruit Australians, and had been trying for four months, to fill a vacancy before nominating a foreign worker for a 457 visa, although there are exemptions."
See more at: http://www.theaustralian.com.au/national-affairs/policy/employers-seek-reversal-of-flawed-457-clampdown/story-fn9hm1gu-1226720497650#sthash.4r8Bgp2O.dpuf