With the latest poll giving Ed Milband a marginal 51-49 lead over his brother, it isn't getting any clearer who is going to become Labour leader in 12 days' time.
What is clear, however, is that the onus is now on David Miliband's campaign to deliver a game-changing moment that will secure his victory.
Accurate polling for this contest is incredibly hard to come by owing to the complexity of the voting system, but the arresting figure from this YouGov/Sunday Times poll is that on first preferences, David leads Ed by four points. Like Harriet Harman before him, if Ed wins this, it's going to be down to the second preferences.
To return to David, and his need to manufacture a defining moment that will swing the contest back in his favour. Just as Ed has increased his emphasis on "moving beyond the New Labour comfort zone" in the past few weeks, David also needs to refine his stance on the Blairite legacy and find a way to appease those who still feel like he should have clarified his position on Iraq earlier in the contest, rather than just attempting to shift the focus of the campaign away from the war.
But an opportunity could be at hand, in the shape of the row over phone-hacking at the News of the World. Matthew Norman, in his media diary column in the Independent today, suggests that David could "clinch it" by pledging to call for an inquiry into the relationship between New Labour and the Murdoch empire.
In his somewhat tongue-in-cheek way, Norman offers various examples of the intimacy between the Blair coterie and News International. But amusing as those vignettes are, I can't help feeling he could be on to something serious here.
There can be no doubt that both Parliament and the public are outraged about the revelations that Andy Coulson, disgraced former editor of the News of the World, now occupies a senior position in Downing Street. Two Parliamentary enquiries and an impassioned series of questions in the House tell their own story. And as my colleague James Macintyre has pointed out, there are deeper issues of the relationship between Murdoch's newspapers and the police to be considered, too.
Perhaps this is just the issue that David Miliband needs to give his campaign that final boost. It enables him to distance himself from Blair and New Labour without really changing his stance on any specific policy issues, while at the same time demonstrating leadership on a contentious issue that has a lot of media traction at the moment. It would also have the added benefit of disarming those New Labour grandees who saw fit to intrude into the contest at the end of last month.
With the contest this close, such a gesture could just make all the difference.