In a major boost to sacked Sri Lankan Prime Minister Ranil Wickremesinghe, the Supreme Court in a landmark ruling on Tuesday overturned President Maithripala Sirisena's controversial decision to dissolve Parliament and halted the preparations for snap polls on January 5.

The apex court's decision deepened the political crisis in the island nation after president Sirisena fired his coalition prime minister Wickremesinghe on October 26 and installed former strongman Mahinda Rajapaksa as the new premier. A three-member apex court bench, including country's chief justice Nalin Perera, delivered its verdict after two days of deliberations on as many as 13 petitions against and five for Sirisena's November 9 decision to dissolve Parliament.