The ballot would allow staff to take industrial action.
The protest follows mounting rebukes of managements’ treatment of casual staff, including investigations into wage theft across 21 universities.
Management is yet to accept the union’s calls for this allowance to be offered annually.
Although the High Court held that enterprise agreements protected academics from censure for their “honestly held opinions.”
Staff are demanding renumeration for six years of unpaid marking and administration work.
The WSU NTEU President said that staff have no choice but to move to industrial action.
“Once again the University's response appears very much to be 'why pay your staff correctly when legally you can get away with underpaying them?'”
In an administrative oversight, at least one staff member was sent the email despite having already been offered a conversion.
Staff have raised concerns the data will be used to rank academics and justify course cuts.
USyd is now the sixth university in New South Wales to have agreed to the NTEU’s demands.