Sri Lankan President Mahinda Rajapaksa has called for an early election to seek a third term in office amid growing criticism of his wide-ranging powers.

The move on Thursday, two years before his current term expires, is seen as an attempt by Rajapaksa to prevent an expected loss of public support if an election were held according to schedule.

Rajapaksa had earlier promised to abolish the presidency because of widespread criticism that the office has too much power and lacks accountability.

However, Mohan Samaranayake, a spokesperson, said Rajapaksa signed a proclamation on Thursday declaring "his intention to be elected for another term".

The proclamation was sent to the Election Commission, which will decide on a date. Senior officials have said the polls are likely in the first week of January.

Two-term limit

Rajapaksa continues to enjoy much of the popularity he gained by ending a 25-year civil war in 2009, but recent provincial elections showed signs of a slide in support amid rising living costs, corruption allegations and a deterioration in law and order.

The main opposition parties are negotiating to field a joint opposition candidate with a pledge to abolish the executive presidency.

Temple aims to heal Sri Lanka's violent past

A cabinet minister from Rajapaksa's ruling coalition resigned on Tuesday in protest against the president's refusal to heed demands that he prune his extensive powers and carry out democratic reforms.

Rajapaksa was first elected in 2005 and overwhelmingly won another six-year term in 2010.

He used his party's parliamentary dominance after that victory to change the constitution and scrap a two-term limit for presidents.

However, some legal experts argue that he cannot contest another election because he was elected for his second term under the old rule.

The Supreme Court - appointed by Rajapaksa under powers he received through the same 2010 constitutional change - ruled earlier this month that he could seek a third term.

The UN is investigating his administration over alleged war crimes during the closing months of the civil war, while his government has been unable to find a political solution to the ethnic problems that led to the war or cope with growing economic hardships.

Rajapaksa has rejected the UN probe and refused to allow investigators into the country.

Source: Agencies