Kevin Rudd is the victim of a clinically planned and terrifyingly efficient political assassination.

The idea had long burned in the minds of some but the final operation was so tightly controlled that its denouement utterly shocked most members of the Labor Party.

Just before the first shot rang out at 7:00pm on ABC News and ABC Online one of the party's elder statesmen, Defence Minister John Faulkner, was in the middle of a pre-recorded interview for The 7:30 Report.

KERRY O'BRIEN: As we've been sitting here recording this interview, I'm told that ABC News is about to go to air, from Canberra, with a story that there are leadership rumblings, as they put it, in Canberra right now as we speak, that factional leaders are in discussion and counting numbers, as I understand it, with regard to a possible leadership challenge. Are you aware of any potential moves on the leadership of Kevin Rudd tonight, not the moves tonight, but the moves?

JOHN FAULKNER: Well, Kerry, I don't know what's on ABC News. All I know is I've been sitting here talking to you and so it might be on the ABC News, well it's also news to me.

It was news to everyone. In the minutes after 7:00pm, in the offices and restaurants and cafes around the Parliamentary Triangle, the mobile phones of Labor MPs and senators lit up. In the early stages ministers and MPs rolled out the usual denials, because they honestly believed it was another beat-up.

The Member for Reid, Laurie Ferguson, said, "I don't know who they are, the ABC knows more than Caucus."

The prime minister was at a function in Parliament House celebrating the 20th year in Parliament for Senator Nick Sherry. Just after 7:00pm many people who were there report that everyone's mobile rang. The prime minister left.

A few tiny flaws in the execution of the assassination plot exposed the final hours of the operation to the arc-lights of the media. Because of the ABC stories, shortly after 7:00pm the halls around the prime minister's office were swarming with journalists and cameras and Julia Gillard's every public movement was being recorded.

There is a novel in this but what follows is one small shard of the plot.

For weeks there had been speculation that the prime minister might be replaced with his deputy. But as long as Julia Gillard remained loyal then without a challenger there could be no challenge.

So there was no genuine threat to Mr Rudd in any real sense until Wednesday. That morning two right-wing powerbrokers, Mark Arbib from NSW and David Feeney from Victoria, went to see Ms Gillard. They were sent away to count.

They returned at noon to say they could deliver a majority of the right in every state. Ms Gillard was in the game and the challenge was on. But they fretted that the entire plot could come unstuck if word leaked that it was on. So they intended to make their final moves late to stay under the electronic media radar.

But there are few perfect operations. There are always fingerprints.

Exactly 12 months ago the tip that Godwin Grech might be something more than just a hapless Treasury official came from a scrap dropped during a casual conversation at Aussies Cafe on the ground floor of Parliament House.

The scent of the Gillard challenge came during a chance afternoon encounter with a Labor powerbroker at the same table.

In the midst of an otherwise harmless chat he dropped his voice, scanned the tables for familiar faces and said with an unusual urgency: "Could we win with Julia?".

Pressed to explain, the conversation ended abruptly: "I gotta go thanks for the coffee."

Something was up. Calls to the likely suspects went unanswered until one picked up at 5.30pm.

"What's happening?" I said.

"What do you know?" he replied.

"I know something's going on. What do you know?"

"Wait until after 8:00pm and I'll give you an exclusive."

"But the news goes to air at seven."

"Wait," he said and hung up.

It was an infuriating conversation because it confirmed a serious push against the prime minister by serious players. But there was every chance it could evaporate because everything depended on how Ms Gillard had responded to their advances.

Comparing notes, it emerged that the ABC's chief political correspondent Mark Simkin was also on to the story.

By 6.50pm we had enough to broadcast that there were moves afoot but that it wasn't clear at all whether they were being supported by Ms Gillard. We made it clear in the stories that we were uncertain of her position and deliberately erred on the side of caution.

But it was still an enormous risk. If she had rebuffed the advances then the conspirators would melt back into the shadows and the next day everyone would, again, furiously deny there was anything going on. And, unlike some other operations, there are serious consequences for being seriously wrong in the ABC.

We knew that the first sign that we were wide of the mark would come by way of an outraged phone call from the prime minister's office to the ABC's bureau chief, Greg Jennett.

That call never came.

Greg and the ABC's tireless chief of staff Simon Johnson began furiously organising resources and dispatching them to the halls and restaurant districts.

In ABC Radio Louise Yaxley was powering through calls and stories and marshalling her team.

ABC TV's Hayden Cooper was trawling the corridors down near the prime minister's office and Lateline's Dana Robertson was tracking down backbenchers.

In Radio Current Affairs Sabra Lane and Samantha Hawley were working the phones and chief political correspondent Lyndal Curtis returned to work from her sick bed.

The new producer for ABC News 24, Michelle Ainsworth, left her children with her husband and returned to work and ABC News Breakfast's Melissa Clarke (who gets to work at 4.30am) was on the phone asking if she should come in.

The rest really is history.

I write all this for two reasons. First, it is a great yarn. Second because the ABC doesn't plaster "exclusive" on every lame rumour and, frankly, does a really poor job banging its own drum.

And I know that in the wash up of this, the story will have 1,000 fathers, as some of the self-basting outlets drown themselves in their own acclaim. That's fine too but I write because I'm bored by reading bile covered tripe in the same outlets claiming the ABC doesn't break stories.

The ABC radio news breaks stories almost every hour. AM is the jewel in the crown of a radio current affairs operation that is unique in this country. The ABC Online site is second to none. ABC Local Radio gives a voice to every community on this continent. And ABC TV News and Current Affairs is the most trusted brand in television broadcasting.

I'm proud of my colleagues and the job they do in the large and small parts of the ABC. And, in the end, the proof of the pudding is in the quality of the ingredients.

As one minister told Mark Simkin: "I didn't know about it. But the fact that the ABC was running it meant it had credibility".

Chris Uhlmann is political editor for the ABC news channel, ABC News 24.