It would be troubling enough if Tony Abbott's shilly-shallying on electoral reform had merely killed off hopes of making overdue changes to the nation's electoral laws.

But it has shredded his credibility too. Credibility he had steadily rebuilt since admitting to routinely gilding the lily, to not always telling the ''Gospel'' truth unless he was delivering scripted comments.

As is the Opposition Leader's wont, he struggled manfully through a difficult press conference on Thursday morning, mostly avoiding questions, all while wearing what he once stylishly characterised in Julia Gillard, as a ''shit-eating grin''.

But spare your sympathies. This was entirely self-generated discomfort.

The package was never going to be popular, particularly because it was headlined by a massive $20-million-a-year allocation of public funding to the major political parties via a $1 per vote formula.

On the plus side though, it contained improvements including greater campaign funding transparency, more frequent and rigorous reporting of donations to parties, and new rules prohibiting foreign donations in cash and property.

Thanks to Abbott's double-dealing, all of that has gone.

The Liberal leader's failings on the collapse of this supposedly bipartisan package, are manifold.

First, his office claimed that the opposition had not seen the legislation. It also was less than upfront on the level and finality of the agreement. Abbott himself then reneged on a written agreement. And finally, if these integrity issues are not enough to raise voter doubts in someone who within months could be prime minister, he revealed himself as a shallow populist.

Since news of the ''secretly'' negotiated agreement was announced at the beginning of the week, Abbott's office has misled and obfuscated.

As the public backlash grew, and as MPs on all sides grumbled at the optics of politicians voting themselves money in the aftermath of a harsh budget, the Coalition deliberately went missing.

By Wednesday evening, with Liberal and Nationals MPs threatening open revolt, Abbott's office was already preparing to walk away despite assurances from the government that the agreement would hold.

Journalists were told repeatedly, that the opposition would decide on the reforms only once it had seen the legislation. Two inferences were clear. One, that any agreement was somehow conditional or contingent, and two, that the opposition was uninvolved in the minutiae to that point.

What we now know, is that the near-complete draft legislation, which reflected fully the discussions of Mr Abbott's own negotiators, federal director Brian Loughnane, and frontbencher, Bronwyn Bishop, had been provided in mid-May. A final version was provided to the opposition last Friday.

And it was that day, to wit last week, that Mr Abbott wrote back to Attorney-General Mark Dreyfus, advising: ''I am satisfied with the agreement reached and indicate the Coalition's intention to support the legislation and to deal with it, as requested, before the end of sittings.''

Several senior opposition frontbenchers were also copied-in to Mr Abbott's personally signed letter.

This whole affair has shown politics at its worst.

A secret deal between sworn enemies, bound together by financial self interest, is a woeful look.

The fact that the alternative prime minister openly pretended to be uninvolved, and then simply reneged on a signed agreement, raises genuine questions of trust and reliability.

But perhaps the most troubling lesson from the whole tawdry affair, is what it says about Abbott's unpreparedness to argue for unpopular reforms, should he become prime minister.

He began his press conference observing that the principle behind the electoral package was sound.

''Look there is an argument for public funding. There is an argument it would make political parties less dependent upon donations that may not always be made for entirely altruistic reasons.''

He is right.

It is telling however, that he has decided not to even try communicating that principle to voters, despite signing his name to it.

Double Dealing Reveals Abbott's Failings