The reasons behind Labour's surge may actually have little to do with recent events within that party, however. They may have a lot more to do with the still very slow erosion of National's support flowing from a combination of 12 months of unrelenting mini-scandals, sideshows and distractions against the backdrop of a sagging economy and more and more job layoffs across the country.
National has worked on the basis that the day-to-day ebb and flow of politics matters less than getting things right in the major policy areas affecting ordinary people's lives - such as making New Zealand's workplaces more productive and more competitive, improving access to health services, lifting academic achievement and so forth.
However, other polls show that the gap between those who think New Zealand is on the right track and those who believe the country is heading in the wrong direction is slowly narrowing.
Along with John Key's slow slide in popularity, that trend is of more worry to National than minor shifts in Labour's support.
Labour would see it differently. First, Shearer can point to having halved the gap between Labour and National in less than 12 months in the job. Second, Shearer and his colleagues end an indifferent year with the polls showing a Labour-Greens coalition being now more than a distinct possibility following the 2014 election.
Labour has not enjoyed that kind of morale-booster since Helen Clark was leader. In the process, the two television polls have snuffed out any lingering thoughts Cunliffe might have entertained of mounting a leadership challenge in February.