Labour's leader, Andrew Little, faces a dilemma over what sort of deputy he needs. Probably he would be happy to retain the party's present deputy, Annette King, but he said a year ago the position would be re-opened about now. Ms King has been excellent in the role - loyal, experienced, sensible in public statements, liked and respected by friend and foe, a safe pair of hands. That is all any leader would want in the person who must stand in for him at times and back him up when necessary.
But whether Mr Little likes it or not, there is much interest in the possible promotion of Jacinda Ardern. She is young, presentable and appears to have a popular following. A political party in Labour's predicament cannot afford to let her appeal go to waste. The party is a year into a third term of opposition and the polls are not yet giving any sign that a change of government is on the cards at the next election.
Labour needs to project the image of a fresh, new potential government. Ms Ardern can help project that image. Ms King cannot. The bigger problem for Mr Little may be that Ms Ardern probably projects that image better than he does, and the last thing he needs is a deputy whose promotion might cause her to be seen as a rival to himself. Ms Ardern no doubt would deny any wish to replace him, and mean it, but if her public reception was much better than his, she would be a contender.
Indeed, if Mr Little is the team player that he appears to be, he would welcome the chance to advance another potential leader for the party. His own leadership is not yet under threat but he has been in the public spotlight for a year and the party probably has some causes for concern. Some feel he comes across as unremittingly grim and humourless. Not everything in politics is of dire importance. Issues such as the flag allow him to lighten up in public if he can.
This time next year, if the polls have not improved for Labour, some in the party may well push for yet another change of leader. Having held two contests in the previous term of Parliament, it is running short of candidates. Grant Robertson, who stood in both unsuccessfully, has accepted he will not be the next leader. Ms Ardern, who was going to be Mr Robertson's deputy had he succeeded, has not been tarnished by the result. She could be a credible candidate; all the more so if by then she has been deputy leader for a year.
Of course, promotion to the deputy's role would carry risks for her. She would be exposed to more critical scrutiny and her political skills might not be up to the combative requirements of leadership. Labour needs to put her to the test sooner rather than later.
In politics there are loyal, safe, non-threatening deputies and there are ambitious deputies, using the post as a step to the top job. Parties in government need the first kind, but in opposition they sometimes need the second. In Jacinda Ardern, Labour would appear to have a potential deputy who would not press for higher office unless the party needed a new leader, and could step up if it did. Labour needs her.