Colombo, Nov 21 (IANS): Sri Lankan Health Minister Maithripala Sirisena resigned Friday and joined the opposition to run for a snap presidential election in January against incumbent President Mahinda Rajapaksa.

Sirisena, 63, who was also general secretary of the ruling Sri Lanka Freedom Party (SLFP), said he had accepted the invitation to be a common opposition candidate, Xinhua reported.

Leader of the main opposition United National Party (UNP) Ranil Wickremesinghe would be the prime minister if he won the vote next year, he added.

Sirisena, who left the government with four other ministers, including Fisheries Minister Rajitha Senaratne, arrived at an opposition press conference with former president Chandrika Kumaratunga who has backed him at the upcoming election.

He said the government has been going in the wrong direction in the recent past and he has also got the support of other opposition parties.

President Rajapaksa, 69, who came into power in 2005, declared his bid Thursday to seek a third term next year. The elections commissioner will announce the election date soon.