Sri Lanka"s political parties are set for a grueling seven-week election campaign after nominations for the presidential polls closed Thursday with the incumbent putting his hat into the ring against his former army commander, according to dpa. President Mahinda Rajapaksa, 64, handed in his nomination from the ruling United People"s Freedom Alliance while General Sarath Fonseka, 58, is contesting the presidency with the backing of an opposition alliance, the New Democratic Front. The election date has been set for January 26. Another candidate raised an objection to Fonseka"s candidacy, saying the general could not contest the election because he was a US citizen, but Elections Commissioner Dayananda Dissanayaka overruled the objection. Fonseka and his family hold US green cards, permits which allow them to live and work in the United States, but he continues to hold Sri Lankan citizenship, a requirement to run in elections. Fonseka, who spearheaded the military campaign against Tamil rebels and led the 26-year-old separatist war to an end in May, decided to contest the election after he fell out with the president and his brother, Gotabhaya Rajapaksa, who is the defence secretary. The general is backed by the main opposition United National Party, led by the opposition leader in Parliament and former prime minister Ranil Wickremesinghe, as well as the third-largest party, the Marxist JVP. "As I defeated the terrorists in the war, I am confident of winning the elections," Fonseka told journalists. President Rajapaksa, who has also been claiming credit for ending the war, said, "I have used my first term to defeat terrorism and want to concentrate on development of the country in the next term." The nominations of 21 other candidates were also accepted, making the field the largest to ever contest a Sri Lankan presidential election. More than 14 million voters have registered to vote. Arjuna Ranatunga, Sri Lanka"s former national cricket captain who led his team to a World Cup victory in 1996 and a lawmaker supporting Rajapaksa"s government defected to the opposition to back Fonseka. "I want to campaign to end corruption in this government," Ranatunga told the media. Rajapaksa, who was elected for a six-year term in November 2005, opted for an early election, claiming he wanted to seek a fresh mandate from the minority Tamils, who were prevented from voting in the previous presidential poll because of a boycott called by the rebels. The opposition charged he called the polls because of his dipping popularity. Both Rajapaksa and Fonseka were due to launch their campaigns Friday. Police have vowed to maintain election laws preventing candidates putting up posters and cutouts. There have already been reports of election-related violence. Seven of Fonseka"s supporters were injured in an attack earlier on Thursday in the southern area of Tangalle.