An audience with the Sri Lankan general whose appetite for power is undimmed

Defeated in this week's presidential election, Sarath Fonseka tells Andrew Buncombe he now plans to stand in the parliamentary poll

It was clear that the former army chief had been expecting a very different outcome. On the dining table at his home in a leafy Colombo neighbourhood was a victory cake baked in the shape of his "Swan" symbol. The artfully created cake, topped with white icing, was untouched.

Sarath Fonseka may have been defeated in Sri Lanka's presidential contest, but he has vowed to stand in forthcoming parliamentary polls to continue to act as a "huge deterrent" to the re-elected Mahinda Rajapaksa. The day after the country's election commission announced that Mr Rajapaksa had won by 17 points, the retired general said he would form his own party or stand as a candidate for an existing one in polls that have to be held by April.

"I have not decided whether it will be an existing one or a new one," he said. "[But] I will ensure I continue to be a huge deterrent to [the President]."

Following Wednesday's release of the outcome of this week's bitterly fought contest, Mr Fonseka and the coalition of political parties he represented said they would mount a legal challenge over the "stolen election" with the country's supreme court. But the former general's revelation that he will also turn his energies to the forthcoming parliamentary polls reflects an acceptance that overturning the outcome of this week's election will be a terribly difficult challenge.

The 59-year-old said surveys taken by his coalition ahead of the polls had suggested that he would win, and that even on election day, early results had suggested that he was more than 1.4 million votes ahead.

"There has been large-scale rigging – they are not stuffing ballots but they are doing computer manipulation," he said. "You can see that the people did not expect this [result]. Normally when there is an election people celebrate for two or three days. You have seen it is very sombre on the streets. For the sake of the people's aspirations we have to get the result cancelled."

Outside, his dog, a noisy dalmatian, was locked inside a kennel because the member of his security detail who had overseen its daily walks had been relocated by the government.

Mr Fonseka, whose house has armed troops on watch nearby, repeated his claim that the government's decision to withdraw his personal security detail was an indication it was planning to kill him. He said his name and a son-in-law's had been placed on an immigration "blacklist" and that they would be unable to leave Sri Lanka. However a presidential spokesman said this was not the case, adding: "He is not on any list. He is free to leave the country."

As Mr Fonseka outlined his plan to continue his political challenge to Mr Rajapaksa, the President again pledged to seek reconciliation with the country's Tamil population. Results showed that while turn-out in the overwhelmingly Tamil north of the country had been low, it had been heavily skewed against the government.

In a statement released by his office, the President said: "The people in Sri Lanka have voted for an end to division, an end to terrorism, and for a new beginning of peace and prosperity. President Rajapaksa intends to ensure that we build on the peace already achieved and move toward a full reconciliation programme."

Dayanada Dissanayake, the country's independent election commissioner, said he had highlighted more than 100 instances of bad practice, in regard to misuse of state resources and unbalanced coverage by state media. He insisted, however, that the election had been largely fair and that there had been nothing untoward on election day.