Someone is taking pot shots at Julie Bishop via The Australian. The question is, who? Is it a lone assassin, a single disturbed individual who has taken it upon himself – or, rather less likely, herself – to take Bishop down? Is it something more organised, a carefully-orchestrated assault? Or is it just that, once there’s blood in the water, all the sharks come in for a bite?

Bishop herself blames Peter van Onselen for having an “unhealthy obsession” with her, and Chris Mitchell and his friendship with the Prime Minister. That’s a bit of a stretch. Accusing The Australian of being pro-Labor is like accusing the Pope of being pro-sex. And particularly as today that Liberal knight-errant Glenn Milne emerges to defend her honour.

Milne of course is contractually obliged to promote the cause of any and all Liberals in the Treasury portfolio, whether they be named Costello, Turnbull or Bishop. But he displayed commendable enthusiasm today in making the case for “an attractive and intelligent blonde.” Milne complains that Bishop and Julia Gillard are “of equal status” but don’t receive equal treatment. Not sure what he means by “equal status”. One’s Deputy Prime Minister and the other isn’t. Remember, your side lost last November, Glenn. Milne also recycles the line Bishop apparently told plagiaree Roger Kerr, that the footnote incident was the fault of Melbourne University Press. It wasn’t.

Undoubtedly there’s frustration within Coalition ranks that Wayne Swan does not appear to be doing the Government’s cause any harm at all. There’s some Canberraitis at work here. What people inside Parliament House, including in the Opposition and the Press Gallery, might think of Swan doesn’t necessarily translate into what voters think. Swan is also the junior partner in the Government’s economic team. The senior partner is of course the Prime Minister, as people expect. Kevin Rudd dominates the public’s perception of how the Government handles the financial crisis. And so far, they like what they see.

The same dynamic is at work on the Coalition side, but it is working to Bishop’s detriment. Turnbull is his own shadow Treasurer. The financial crisis is his sort of issue and he has dominated the Opposition’s response to it. Bishop has been lucky to get a word in edgeways, particularly when the time difference means it’s hard to break into the east coast morning media cycle from Perth. It hasn’t helped that Turnbull likes to hog the Dispatch Box in Question Time.

The lack of polling lift from Turnbull’s elevation may also be starting to eat away at MPs. Turnbull is performing strongly enough that no criticism could be directed at him. Bishop might make for a useful surrogate target.

So who is after Bishop? Let’s consider who benefits and who doesn’t from all this:

Malcolm Turnbull. He needs instability and speculation like a hole in the head. A shadow Treasurer who spends half a press conference answering questions about her own position isn’t much use.

Andrew Robb. Most likely to replace Bishop in the shadow Treasury job and therefore a suspect. But Robb is the oldest and wisest political brain on the frontbench and, while a Turnbull supporter, hated the undermining of Brendan Nelson. His preference was for everyone to get on with doing the jobs they’ve got as well as possible, rather than more self-obsession.

Joe Hockey. Hockey has been a lot more visible as Finance spokesman than he ever was as… whatever his previous portfolio was. Actually, it was Health, but you’d never have known. A prime suspect, although there’s plenty on both sides of politics who wish he’d replace Barry O’Farrell’s and give NSW a competent government. The one problem with Hockey as shadow Treasurer is that Turnbull is from Sydney as well, but if Robb got the job, the leadership could more easily cover Sydney, Melbourne and Perth.

Peter Dutton. Vociferous in support for Bishop yesterday. A long shot for shadow Treasurer, though he gets more time at the Dispatch Box than many and was the last Assistant Treasurer.

Christopher Pyne. The usual suspect for all leaks during the short reign of Brendan Nelson (at least according to Nelson supporters) but has recently been more productively employed in Education – about Turnbull’s best pick on his frontbench.

Tony Abbott. Afflicted by an acute case of verbal diarrhoea in the last days of Nelson, Abbott has been quiet lately… too damn quiet. This is the bloke who missed out on a new portfolio even after he publicly complained about having Families and Indigenous Affairs. Gets more time at the Dispatch Box on points of order than asking questions.

Peter Costello. The once and future prince sits quietly on the backbench, occasionally offering his own take on economic events – views that attract a lot more attention than Bishop’s. Tony Smith was demoted to shadow assistant Treasurer by Turnbull. Playing the long game of waiting for Turnbull to trip up, or – here’s a long shot – maybe hasn’t made up his mind what he’s doing. Unlikely to leak to former Howard spokesman Dennis Shanahan. But then, that’s just what he’d want us to think, wouldn’t he …