SRI Lanka last night handed its President absolute power – and in the process anointed another South Asian political dynasty – with parliament rubber-stamping constitutional changes that critics have warned will spell the death of the region’s most enduring democracy.

President Mahinda Rajapakse secured the two-thirds parliamentary majority required to rush through the controversial 18th amendment, scrapping the two-term presidential limit and letting him appoint judges, police and election commissioners, and central bank officials.

The amendment passed with 161 votes in the 225-member parliament. Seventeen MPs voted against while the main opposition United National Party boycotted.

“We don’t want to be contaminated by this undemocratic act,” UNP leader Ranil Wickremesinghe said yesterday, as he joined other opposition politicians in an angry demonstration outside parliament. The changes have been condemned by lawyers, rights activists and some religious groups.

Under the previous 17th constitutional amendment, the appointments power was invested in a nominally independent 10-member Constitutional Council to avoid centralising power in the hands of one autocratic figure.

Mr Rajapakse, who was re-elected in January for another six-year term after securing victory against the Tamil Tiger separatists, has argued he needs more time to steer the country’s economic development following three decades of civil war.

He has dismissed claims the constitutional changes are undemocratic, saying a president must still be elected to govern.

But the Colombo-based Centre for Policy Alternatives executive director Paikiasothy Saravanamuttu said that argument ignored widespread concerns raised during this year’s elections, including by the country’s election commissioner, that the government had abused state resources and power to secure victory.

“This is about consolidating power, establishing authoritarianism and trying to ensure – as far as he’s concerned – there’s a clear line of succession,” Dr Saravanamuttu told The Australian, saying the changes could lead to new conflict.

The government is already dominated by the Rajapakses – the President’s three brothers all hold important ministerial posts, and one of his sons, Nimal, is an elected MP.

The Hong Kong-based Asian Human Rights Commission said the amendment marked “the end of liberal democracy” in Sri Lanka.

In an open letter published in the country’s liberal-leaning Sunday Leader, civil rights activist Suriya Wickremasinghe warned that the constitutional amendment would “further entrench the worst features of the presidential system of government under the present constitution”. He said the two-term limit and Constitutional Council were the only checks on the already powerful President, who remains immune from prosecution during his term in power.

“If the term limit is to go, then the immunity conferred on the President must also be removed,” Mr Wickremasinghe said.

“For the knowledge that – at a definite time within the foreseeable future – the President will once again be legally accountable for acts committed while in office is a powerful deterrent against misuse of power.”