Estimates of the number of people at this rally in Karachi for Pakistan cricketer-turned-politician Imran Khan vary wildly.<br/> But even the lowest figure of at least 100, 000 makes this one of the largest political rallies Karachi has seen in recent years.<br/> Khan's promising to tackle Pakistan's endemic corruption if he becomes prime minister.<br/> SOUNDBITE: Imran Khan saying (Urdu):<br/> "I assure you that you don't need a rocket scientist here in Pakistan. We just have to correct the system. We have to bring in an honest team that is accountable to itself."<br/> The rally's come at a time of tension between Pakistan's civilian government and the military it's accused of plotting a coup after the U.S. raid that killed Osama bin Laden.<br/> Polls suggest Khan is Pakistan's most popular politician.<br/> But popularity doesn't necessarily translate into power.<br/> Most of Pakistan's voters live in rural areas where feudal relationships determine generations of political loyalty.<br/> Paul Chapman, Reuters
