Sydney: Sri Lankan President Mahinda Rajapaksa said his party’s election win in Eastern Province, almost a year after the army seized the region from rebels, is a “mandate" to drive the Tamil Tigers from their last strongholds in the north.

The United People’s Freedom Alliance won 20 of the 37 seats in the provincial council in an alliance with the Tamil Makkal Viduthalai Pullikal, or TMVP, a party comprising defectors from the Liberation Tigers of Tamil Eelam, or LTTE.

“The people of the east have given a clear mandate of peace through the defeat of terrorism," Rajapaksa said in a statement on Sunday. Opposition parties accused armed groups of threatening voters.

Taking on the Tigers: Sri Lankan President Mahinda Rajapaksa.

Voters in Batticaloa, Ampara and Trincomalee districts elected members of the Eastern Provincial Council two days ago after choosing nine local councils in the area in March. The TMVP, the pro-government breakaway faction of the LTTE, won control of eight local councils in the March balloting.

The opposition, United National Party, and its allies in the Sri Lanka Muslim Congress won 15 seats in the 10 May ballot. Two smaller parties won a seat each. The Tamil National Alliance, or TNA, the main Tamil party, boycotted the vote.

The opposition condemned the vote as flawed. “We will challenge the verdict as this is daylight robbery," Muslim Congress head Rauff Hakeem said in a telephone interview from Colombo. “We are approaching the election commissioner to tell him about the systematic rigging that was openly done."

The opposition is planning to meet in Colombo “in a couple of days" to decide on whether to start legal action to try to overturn the result, Hakeem said.

Turnout of 60% of the one million registered voters was a “great success," foreign minister Rohitha Bogollagama said in the UK on Sunday, according to the defence ministry’s website.

The government’s power-sharing plan is based on a 1987 constitutional amendment that provides for establishing provincial councils in the north and east. LTTE, which is designated a terrorist organization by the US, the EU and India, rejected the plan in 1988 saying too much power was left with a national parliament.

Eastern Province, which accounts for 15% of Sri Lanka’s land area and 7.9% of its population, contributed less than 5% of gross domestic product during its occupation by rebels, according to Sri Lanka’s central bank.

The government is seeking $1.8 billion in aid to rebuild the province and bring investment and tourists to the region that has a 426km coastline.