Just a few months ago, Sri Lanka's president and its army chief were strong allies, working closely together to defeat the Tamil Tiger rebels and end the nation's 25-year civil war.

Now the two men hailed as national heroes are bitter political opponents, as Gen. Sarath Fonseka works to unseat President Mahinda Rajapaksa in next month's presidential elections.

Rajapaksa's allies brand Fonseka a potential dictator and say he is ungrateful to the man who promoted him to army chief and put him in charge of leading the fight against the rebels.

Fonseka, who resigned from the military last month, accuses Rajapaksa of corruption and nepotism and says the nation is still not at peace, even though the war ended in May.

"Under cover of war victory, if someone is trying to boost up his family image or to stick to nepotism ... then you can't say peace has come," Fonseka told The Associated Press in an interview Thursday.

Fonseka was highlighting the position of Rajapaksa's three brothers: one a Cabinet minister, another the president's top adviser and a third the defense secretary.

Fonseka said if elected he would prune down the extensive powers of the presidency and strengthen parliament under the prime minister.

But many Rajapaksa backers argue Fonseka is actually planning on taking more power, and might even turn the country into a dictatorship.

Fonseka brushed off the accusation.

"If I was keen about a military regime, I would have done it long ago, even before the war was won," he said. "I am a disciplined general who commanded a disciplined army."

The falling out between Rajapaksa and Fonseka is stark. After the war, the president promoted the army chief, giving him a fourth star and naming him commander of all military forces.

But Fonseka complained he was sidelined into a bureaucratic job and under constant accusation of plotting a coup. He resigned last month and announced he would run as the opposition candidate in Jan. 26 elections.

Victor Ivan, a political analyst and editor of Ravaya newspaper, said Fonseka's decision has made the election _ which had been considered an easy win for the president _ a real contest and was healthy for democracy in the country. But also he warned of a close race sparking street violence.

The government and the military came under harsh criticism for their conduct during the final months of the war, when 300,000 ethnic Tamil civilians were trapped along with Tamil separatists in a shrinking war zone in the north.