Sri Lanka's President Maithripala Sirisena has appointed his predecessor, Mahinda Rajapaksa, as the country's new prime minister after the collapse of the governing coalition.
He dismissed Prime Minister Ranil Wickramasinghe after the party's United People's Freedom Alliance (UPFA) had been dissolved by the government
Mr Sirisena beat Mr Rajapaksa in the 201
Opponents say the move be unconstitutional.
Wickramasinghe helped lead the president to triumph in the 2015 poll, but the pair is said to have recently contradicted in the Cabinet Government plans to lease a port to India.
The Prime Minister and his United National Party (UNP) came to power promising responsibility for alleged atrocities in the Sri Lankan civil war and Rajapaksa government
Finance Minister Mangala Samaraweera described his leader's dismissal as an "anti-democratic coup" Mr Wickramasinghe said the leader remains because he could not be constitutionally removed by the president.
And cabinet spokesman Raitha Senaratne told the BBC that Mr. Wickramasinghe remains the country's prime minister.
President Sirisena was an ally of and minister under Rajapaksa before he turns against him
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Mr. Rajapaksa ended the civil war in 2009, but was criticized for the means by which he had won the victory – many thousands of Tamil civilians were said to have been killed in the last months of the fighting by government forces.
The 26-year conflict between 80,000 and 100,000 people has probably died, with both sides allegedly committing war crimes.
In addition, the former president is also accused of corruption on an epic scale, along with his inner circle.
President Sirisena told the BBC shortly after his election victory that he was planning an internal investigation into the alleged atrocities of the Civil War.
But bad headlines have dogged the president in recent weeks and damaged his image.
Mr. Sirisena had to call Indian Prime Minister Narendra Modi earlier this month after reporting that Indian intelligence was planning to kill him at a Cabinet meeting.
And in September he railed against the national airline Sri Lankan Airlines for serving him cashew nuts.