SUPPORTERS and foes of Afghan President Hamid Karzai agree on one thing: his rivals must unite to have any hope of mounting a serious challenge in an upcoming presidential poll, and that looks increasingly unlikely. This week marks the start of a two-week registration period for candidates to sign up for the Aug. 20 vote. A wide selection of technocrats, ex-cabinet ministers, regional bosses and perhaps even an ex-US ambassador have hinted they may run. The poll will be a defining event for Afghanistan, even as thousands of additional foreign troops are being poured into the country to battle an escalating Taleban insurgency. Karzai, who was installed in power in 2001 and won the country's first democratic election in 2004, has since lost much of the enthusiastic support he once enjoyed among both the public at home and his backers in the West. Yet the opposition has had little success agreeing on a standard bearer. A leader long seen as weak, Karzai appears to be in as strong a position as ever ahead of the vote. Anwar-ul-Haq Ahadi, a likely candidate and former finance minister, told Reuters key contenders have met several times to field a single rival against Karzai, but had not agreed. “Unfortunately, there has been no agreement so far. Each thinks his chance of victory is greater than the other,” he said. Among other challengers are ex-Foreign Minister Abdullah Abdullah, ex-Finance Minister Ashraf Ghani, Nangarhar Province Governor Gul Agha Sherzai and perhaps even Zalmay Khalilzad, an Afghan-born ex-US ambassador to Afghanistan, Iraq and the United Nations. Abdullah is expected to stand as the candidate of the main opposition bloc, the National Front, which was formed two years ago hoping to build a coalition across feuding ethnic groups to unseat Karzai. But with the vote looming, the bloc appears to be divided by ethnic factionalism. Several of its founders have voiced disagreement over who should be their candidate. Last week the Alliance said one founder, powerful former deputy president Mohammad Qasim Fahim, had deserted the group to back Karzai. “The Front is no longer united. It could not shine as expected, given its political and ethnic broadness,” said Helaluddin Helal, a former deputy interior who now sits in the parliament and is a critic of the president. “The only way for the candidates to defeat Karzai is through forming a team or a front,” Helal said. Other groups Karzai is a member of Afghanistan's largest ethnic group, the Pashtuns. Fahim is a rich Tajik, a member of Afghanistan's second-largest ethnic group, who commanded the anti-Taleban forces that ousted the mainly Pashtun militants in 2001. If Karzai has Fahim's support, the president can now court leaders of other groups, such as the Hazaras and Uzbeks. Many of his key rivals are technocrats who also served as ministers in his government and have double citizenship in Western countries where they lived in exile. They lack traditional power support bases and are seen by critics as out of touch with Afghanistan's day-to-day realities. Even critics of Karzai think his rivals are flawed. “Karzai's key rivals are those who served under him or worked with him and were involved in corruption and in inefficiency in the past. People will ask ‘Are they any better than him?',” said Daad Noorani, a political analyst and opponent of Karzai. Some key Pashtun tribes have agreed to back a single candidate to avoid splitting the Pashtun vote, Noorani said, adding that their choice seemed to be Karzai. Karzai has had trouble in the past winning support among some Pashtuns who saw him as an American puppet. But lately he discussed efforts to negotiate with the militants and has criticized Western troops for killing civilians, steps that will win some sympathy among disgruntled Pashtuns. His access to government resources, especially helicopters and security forces, will give him advantages in his campaign. “I have my manifesto ready,” Abdul Ali Seraj, a member of Afghanistan's former royal family who intends to stand against Karzai, told Reuters. “But at the end of the day, I have to go to all of the 34 provinces to talk about it to people and my supporters. I can't. I don't have the resources.” The stance of the United States could also play a role. Washington, which calls Afghanistan its top foreign policy priority, says it is not picking sides. But many Afghans believe that the United States has too much money and too many troops in their country to leave the outcome to chance.