Opposition Leader Bill Shorten’s decision to identify himself as the subject of a police investigation into sexual assault allegations when he was a teenager was made in anticipation that News Corporation would attempt to use the story against him, Labor figures say.

The lengthy investigation concluded this week, with police deciding not to recommend charges in relation to events involving Shorten and an unnamed woman at a Young Labor event in the 1980s. Yesterday, Shorten confirmed what had long been discussed on social media, that he was the target of the allegations.

The Australian newspaper has run several pieces on the investigation into a “senior Labor figure” over the last year. Most pertinently, it ran a column by right-wing industrial relations columnist Grace Collier in The Weekend Australian last Saturday, which warned that even if charges were not laid, it would still “be a disaster for Labor”. Collier, who famously claimed that prime minister Julia Gillard was in no position to complain of misogyny because she showed too much cleavage in Parliament, collaborated on the hounding of Gillard over the AWU corruption matter from the 1990s with far-Right blogger and sacked shock jock Michael Smith, who has enthusiastically aired the rape allegations about Shorten.

The column was seen by some in Labor as a blunt warning that, regardless of the truth of the allegations, News Corp would run the same sort of smear campaign against him that it ran against Gillard, which continued for over a year despite a complete absence of any specific allegations against her.

However, a direct attack designed to destroy Shorten, who has proved unexpectedly competitive against a government that has spent a year stumbling from error to error, may not have been the only thing playing on Labor minds. One of the key elements of Rupert Murdoch’s success, according to The Guardian’s Nick Davies, is his ability to secure cooperation from key figures based on the threat that they will be punished via personal attack in his newspapers. As Davies wrote in July:

“At its worst, everybody in the power elite has heard that the punishment can amount to crude blackmail. They have all heard the stories about how Murdoch editors have safes containing dossiers of evidence about the private lives of politicians and competing businessmen; and that Murdoch and his people agree to suppress these gross embarrassments in exchange for yet more favours. There are specific rumours — about a senior figure in British sport who is said to have complied with Murdoch’s plans for TV rights when he was informed that The Sun was ready to tell its readers that he had had sexual relationships with young men; and about a middle-ranking Labour politician who is said to have spoken up on behalf of Murdoch’s UK newspapers after journalists obtained a video of him having sex with a prostitute while the prostitute’s husband watched. It is true that the sports administrator and the Labour politician offered their support to Murdoch. Whether they did so out of fear of the dossiers — or whether the dossiers even exist — is not so clear. The power is in the belief and in the fear it engenders. Which is widespread.”

In this context, the allegations against Shorten, even if police had decided not to proceed with them, were perhaps more damaging if they remained unused by News Corp, kept in the safe, with an implied threat that they could be pulled out if Shorten was seen to be a threat to the company, or if a specific favour was needed. And the threat can always remain implied — it is given force by the few occasions it is publicly delivered on. As Davies notes:

“The power to conceal or reveal sensitive personal information turns out to be just like the power of the bully in the school playground. The bully need only batter one or two children for the fact of his power to be established: fear will then ensure that the others do all they can to placate him.”

Whether in response to the prelude to an attack or to prevent the threat of future attack, Shorten has opted to attempt to short-circuit the issue by coming out, unexpectedly, and on his own terms, to discuss it. It’s true that the allegations were already widely circulating online; this is not the 1980s, when mainstream media journalists and editors could act as gatekeepers of personal information about politicians. But it’s a high-risk play in that it elevates what until now has amounted to social media abuse into a mainstream media issue that can be openly discussed. Shorten himself has now made it the subject of public debate. But it also undermines the threat from Murdoch on the issue: his papers can still run a smear campaign against Shorten, but he has got on the front foot and ensured it can’t be used to blackmail him.

How much the decision costs him remains to be seen. But for the moment, Shorten’s initiative looks the smarter long-term play than staying silent.