Initially, Bishop thumbed her nose at questions over a A$5227 ($5795) short helicopter trip from Melbourne to Geelong to attend a Liberal Party fundraiser. It was put on the taxpayers' tab and would have taken less than an hour by car, but the former Howard Government minister said the flight was "within the guidelines and entitlement". The same justification has been used for attending weddings of Liberal Party friends, and expenses last year that exceeded A$800,000 - more than half of which were travel related.
The controversial Victoria trip last November included another A$4000 in flights, chauffeured limousines and other claims. The Speaker has remained tight-lipped on whether she attended events other than two party fundraisers and Melbourne's Spring Racing Carnival.
When the chopper trip was disclosed last month, Bishop told voters it was necessary because she worked so hard for the country.
The journey towards Thursday's belated mea culpa has been agonising. First Bishop offered to repay the cost. Then Abbott put her on "probation".
But the issue has remained atop the Government's agenda, not least because of critical interventions from within its own ranks. Some have been more subtle than others, as Abbott minister and leadership rival Malcolm Turnbull live tweeted his own trip from Melbourne to Geelong - by tram and train.
Bishop made her first scripted apology to the Liberals' favourite radio shock-jock, Alan Jones. "I was short of time, but it is no excuse and it was an error of judgment," she said of the "ridiculous" flight. She also said she'd repay wedding expenses which "while technically in the rules, just doesn't look right".
"I want to apologise to the Australian people because I feel I've let them down," she said.
Bishop, who insists the apology is genuine, later said she wished she had said sorry two weeks ago. But she continues to refuse to fall on her sword.
Yesterday's headlines calling for Bishop's head made grim reading for those hoping she could survive. To the frustration of many colleagues, Abbott continues to resist taking action out of fierce loyalty and an ingrained instinct to avoid giving opponents a win.
Yesterday he again said he understood people's anger, adding Bishop was "obviously deeply remorseful" and a "very, very chastened person indeed".
The PM is also wary of the potential for the scandal to blow out into wider scrutiny of parliamentary entitlements and the flexible guidelines that govern them.
But with continuing public fallout, the question is no longer if, but when Bishop will be forced from office.