Reuters Francois Hollande's victory in a left-wing primary gives him the best chance in a decade of bringing the French Left to power, but he will need to rally rebel groups and clarify his policies to fend off charges of weakness. The mild-mannered Hollande showed he could bring together a fractious center-left on Sunday when he beat Martine Aubry, the Socialist party chief, by a wide margin in a primary run-off that drew nearly three million left-wing voters. Hollande embraced his defeated rival after she threw her support behind him in a concession speech. Yet the show of unity after his victory did not include the Left Party or the Greens, whose support is key if he is to beat President Nicolas Sarkozy in a 2012 election. Far from falling into line, the leaders of both parties want clear pledges from Hollande on issues that matter to them: an exit from nuclear power for the Greens' Eva Joly, and higher capital gains tax for the Left Party's Jean-Luc Melenchon. Arnaud Montebourg, an anti-globalization candidate who took 17 percent of votes in the primary's first round, said he backed Hollande personally but asked him to promise that he would bring French banks to heel if elected. “Hollande's fairly moderate position on many subjects — the issue of banks is particularly sensitive nowadays — sets him on a collision course with the (more left-wing) groups that were deprived of media attention during the primary season,” said Jerome Fourquet, analyst at the IFOP polling agency. “Aubry was much more compatible with the Greens, for example... There will have to be a process of harmonization of positions if they don't want the base to fracture,” he added. So far Hollande has said he would tighten supervision of bailed-out banks, pare France's reliance on nuclear energy to 50 percent of its consumption by 2025 from 80 percent at present, and make taxation fairer. He did not, however, provide details about how he would enact such policies. In a first shot over the bow after the primary, the Greens' Joly told Le Monde in an interview that the Left would be “crazy” not to make a complete exit from nuclear power. Meanwhile, Melenchon has branded Hollande's program a “minimum solution for the left”. On the financial front, Hollande has resisted prodding from Montebourg to agree that a government official with the power of veto should be placed on the boards of bailed-out banks, despite polls showing that a majority of left-wing voters favor nationalization. In an orthodox step without precedent for a Socialist candidate, Hollande pledged during his campaign for the primaries to balance France's budget by 2017 if elected, but again stopped short of detailing how he would do so. Pollsters say that Hollande is being vague intentionally to avoid alienating left-wing voters, or provoking the sort of internal strife that many on the Left say cost Segolene Royal during her 2007 presidential run against Nicolas Sarkozy. “He has to be careful not to start too soon, not to unveil everything six months before the election,” said Bruno Jeanbart at pollster OpinionWay. “It's fair to say that his lack of precision is purposeful, to better prepare for what's ahead.” Still, as the Left's clear front-runner, Hollande will have to define his positions more clearly before he faces off against President Nicolas Sarkozy in an April, 2012, election. __