The deputy Liberal leader and Foreign Minister reportedly did her nut - or went bananas - in Abbott's office after Fairfax Media reported the inclusion of her unofficial chaperone. This aspect has been denied. Foreign Minister Julie Bishop and Prime Minister Tony Abbott have enjoyed a strong working relationship, but a lack of trust could bring that undone. Credit:Alex Ellinghausen But whether it was a heated confrontation or a calm exchange, the meeting apparently took place and that alone reveals Bishop's nose was out of joint over what would inevitably be seen as a reflection on her abilities and/or her trustworthiness. It is being surmised that the PM wanted the sceptical Robb along for the ride because the flinty negotiator is less likely to be swept up in growing international momentum towards tougher emissions targets. Abbott was initially going to let the Lima conference slide by with no ministerial representation.

But having witnessed the partial hijacking of the G20 on climate grounds, and having read Abbott's post summit comments as portending a more progressive stance into the future, Bishop counselled in favour of Australia's top-level participation. Namely, her own, as the minister charged with such international negotiating responsibilities. Abbott agreed but with one condition: Robb too. Both ministers were advised in writing by the PM last Thursday. Robb's performance stitching up three complex free trade deals has been one of the government's success stories. His effectiveness in international negotiations is now a given. But Bishop has been the undisputed stand-out minister in this government - especially if popularity means anything, as it should to this mostly unloved administration. The idea that the Foreign Minister might not enjoy the unqualified support of the PM is a serious one. Grave even. Just weeks ago she was good enough to chair the UN Security Council. Before that, she successfully wrangled the same notoriously riven body to unanimously adopt a tough resolution on MH17.

Smaller slights than this have proved the defining moment in the descent into division of governments past. A bushfire can begin with just one match Her diplomatic achievements have attracted the government's most glowing tributes. Clearly there is a danger in making a mountain out of a molehill with this story. Bruised egos can heal. Bishop and Abbott have worked extremely well together until now. Yet smaller slights than this have proved the defining moment in the descent into division of governments past. A bushfire can begin with just one match. And politics offers the perfect conditions for the slow burn.

Kevin Rudd's relationship with his deputy, Julia Gillard, was irreparably damaged when she read his (admittedly paranoid) number counting as tantamount to branding her disloyal. Way back in 1971, Malcolm Fraser resigned from John Gorton's cabinet claiming disloyalty from above. It fomented a crisis which helped end Gorton's leadership. Unity has been the defining characteristic of the Abbott cabinet. Loading Abbott's provocative insistence on Robb's attendance in Lima may have put the first crack in that.