Twenty years after Asif Ali Zardari shot to political fame when his late wife, Benazir Bhutto, became the first female Muslim prime minister of an Islamic country, the leading candidate to be Pakistan's next president is again battling his past.

The 54-year-old former businessman has spent more than half his 20-year political career in prison in Pakistan fighting corruption charges and most of his recent past in exile fighting off similar allegations in international courts. In the wake of his wife's assassination last December and the decision by former general Pervez Musharraf to step down as president last week there has never been a more pressing moment to present his side of the story.