Back from Exile, Cambodia's Opposition Leader Brings Thousands onto the Streets Heng Sinith / AP Sam Rainsy, President of Cambodia National Rescue Party greets his party supporters during the arrival at Phnom Penh International Airport, in Phnom Penh, Cambodia, July 19, 2013. "I have returned to rescue the country," Sam Rainsy told the cheering crowd of thousands gathered Friday morning at Phnom Penh Airport. Cambodia's opposition leader has landed amid a general election campaign in full swing - elections are slated for July 28 - but can be forgiven for missing the first three weeks of campaigning. Convicted in absentia for racial incitement and destruction of property, charges he insists were politically motivated, the 64-year-old has spent the last four years living in exile, mostly in Paris, until a royal pardon facilitated his return as head of the Cambodia National Rescue Party (CNRP). Prime Minister Hun Sen, whose authoritarian rule has spanned 33 years, has faced increased pressure from the international community to allow a free and fair election. Yet many people remain perplexed by the sudden change of heart that allowed his bitter rival's return. And no one, least of all Sam Rainsy, believes the looming poll will be clean. There is little doubt that Prime Minister Hun Sen will soon to extend his time in office by another five years. His Cambodian People's Party, or CPP, has guided the nation from the end of Pol Pot's murderous Khmer Rouge through a period of stability and guarded prosperity. Yet his position hardly stems from popular assent. The CPP controls every form of governance, including appointing judges, police officials, village headmen and even the National Election Committee. Cambodia is blighted by "systemic corruption so we have to put our house in order," Sam Rainsy told TIME prior to his return. MORE: Cambodia Election Campaign Promises Little Change Yet taking on Hun Sen remains a colossal task. The former Khmer Rouge battalion commander, who lost an eye in combat, was first installed as Prime Minister in 1985 after defecting to the Vietnamese, who were occupying Cambodia at the time. The CPP lost the country's first democratic elections to Prince Norodom Ranariddh in 1993, but the prince decided to share power in the spirit of reconciliation. Such munificence was wasted on Hun Sen, however, who launched a coup four years later to regain his position as Cambodia's sole leader. Little has changed since this time, and although Khmers regularly go to the polls - 9.6 million are currently registered to vote under the gaze of 7,700-odd domestic and international observers - nothing is left to chance. Last month, all 28 opposition MPs were expelled from parliament (after the CPP, which holds 90 of 123 seats, decided to disqualify members of the two separate opposition parties that merged to form the CNRP). Local officials, all working under the auspices of the CPP, tightly control voter lists. Anyone thought to support the opposition can be summarily struck off, while legions of "ghost voters" swoop in to sway borderline ballots. Opposition groups allege that 10% of legitimate voters are turned away from polling stations; another 10% of voters are engaged in fraudulent practices that prop up the incumbents. So while the veneer of democracy is served by Sam Rainsy's presence, "it will not change fundamental flaws in the election process, from the imbalance in the media, flawed voters list, and partial election management body," says Laura Thornton, Cambodia director for the National Democratic Institute. Sam Rainsy is under no illusions about what lies ahead. After fleeing Cambodia as a 16-year-old following the murder of his father, he returned in 1992 and briefly held the post of finance minister. A protracted battle with Hun Sen then forced him into exile in 2005, accused of defamation. A royal pardon was issued a year later, but fresh charges arose in 2009 when, in an ill-advised media stunt, he removed six demarcation posts at the Cambodia-Vietnam border - a much disputed frontier. Despite his latest reprieve, he is not registered to either vote or stand as a candidate in the upcoming election, and his role must likely remain that of cheerleader. MORE: In Cambodia, China Fuels Deadly Illegal Logging Trade As with all elections, the Fourth Estate has a huge roll to play in Cambodia this month, and, through nepotism or intimidation, virtually all media back the CPP. Earlier this month, Hun Sen banned foreign media broadcasts in the country, but made a swift U-turn amid an international uproar. Voice of America and Radio Free Asia are the only Khmer-language media that carry opposition views. Even Sam Rainsy's return is receiving minimal coverage in Khmer language press, according to Thornton. Hun Sen has meanwhile embraced alarmist rhetoric - warning of an "internal war and external war" and, curiously, of an epidemic of collapsing bridges should the opposition triumph. So why did Hun Sen ask King Norodom Sihamoni to allow Sam Rainsy's return? A few say that the death of Hun Sen's father, Hun Neang, on July 12 at the age of 89, prompted some soul-searching. But the most likely answer is aid. The U.S. has been vocal in calling for free and fair elections, and human rights dominated conversation when President Barack Obama arrived in Phnom Penh for frosty talks in November. Cambodia has a distinct aid culture - there are currently 2,465 registered nongovernmental organizations and associations, according to the Ministry of the Interior, giving one of the highest charity per capita rates in the world. USAID foreign assistance to Cambodia amounted to $76 million in 2012, and it is due to slightly increase this year.The freezing of these funds will be hugely unpopular domestically. Sam Rainsy's combative rhetoric will undoubtedly enthrall in the 10 days until polling, and is very likely get him into fresh trouble on the way. CNRP officials tell TIME that half-a-million people lined the street from the airport to Freedom Park where he addressed the crowd, and that the 10-mile journey took five hours. Local media heralded the homecoming as possibly the largest opposition rally the country has ever seen. "I think we are entering a new phrase in Cambodia history; it is the beginning of something like the Arab Spring," Sam Rainsy told TIME by phone from Phnom Penh on Friday evening. Despite this optimism, huge barriers must first be overcome before democracy in Cambodia is anything more than a cynical façade. MORE: A Tale of Two Factory Disasters: What Cambodia Can Teach Bangladesh