Former President Mahinda Rajapakse was sworn in as the new Prime minister, pushing the country in a constitutional crisis.
Ranil Wickremesinghe, who was replaced, has claimed that he is still the Prime Minister.
Mr. Rajapaksa was administered oath on Friday evening by the President Maithripala Sirisena at his office in Colombo.
However, the United National Party (UNP) led by Mr. Wickremesinghe has opposed the development terming it as unconstitutional and illegal.
A former minister termed it as an anti-democratic coup.
Earlier, the United People’s Freedom Alliance (UPFA) led by President
Sirisena has decided to leave the unity government led by Mr. Ranil Wicremsinghe.
President Sirisena’s Sri Lanka Freedom Party (SLFP), the main constituent party of the UPFA and Prime Minister Ranil Wickremesinghe’s had formed a unity government in August 2015 following the elections.
However, there has been growing tensions between the two sides on several policy matters. President-led UPFA has 23 MPs while rest of 69 support Joint opposition led Mahinda Rajapaksa.
Mr. Sirisena had left SLFP in 2015 Presidential polls to contest against the then President Mahinda Rajapakse and was victorious.