General Fonseka addressing National Lawyers Association in Colombo said that he will contest the upcoming Presidential election as a common opposition candidate and will work towards abolishing the Executive Presidency.

"I would definitely defeat the incumbent President Rajapaske", responding to a question he said.

His announcement sets the scene for a stand-off with President Mahinda Rajapaksa, who's called the election two years ahead of schedule.

General Fonseka is reported to be at odds with the government over who should take credit for Sri Lanka's final victory over a decades-long Tamil Tiger insurgency.

Two main opposition parties have said they will support the former military chief.