Julia Gillard's performance as PM continues to disappoint. Tony Abbott & Co. have easily been able to use this to inflame rabid journalists who want their pound of flesh now; inciting the herd.
As per the poll data you quoted Gillard is politically dead in the water & about to deteriorate into a rotting carcass. Somewhat reminiscent of John Howard's Govt. by late 2006.
The public judged that Howard had become too tricky by half - History repeats after all!
Just as the spineless sycophants of the Liberal Party who ignored change management theory denied Peter Costello his opportunity for a moment in the sun; Labor's sycophantic, faceless pollies refused to replace Gillard.
Well the budget is now out there, the reactions are at best mixed & once again Gillard & Swan have comprehensively failed to effectively communicate with the public.
The only ones who don't realise that it's 'game over' are those in the Labor Caucus!