NEW DELHI — Sri Lanka’s political crisis appeared to edge toward a resolution Friday when one of the two men claiming to be the country’s rightful prime minister agreed to step down.

Former President Mahinda Rajapaksa planned to relinquish his claim to be prime minister in an address to the nation on Saturday, according to officials in his party. The current president, Maithripala Sirisena, appointed him as prime minister in late October, but the pair failed to clinch the majority in Parliament needed to secure their power. Mr. Sirisena then dissolved Parliament in November.

On Thursday, Sri Lanka’s Supreme Court ruled that the dissolution of Parliament had been unconstitutional, striking the final blow to Mr. Sirisena’s and Mr. Rajapaksa’s plans to take over the government.

The legally recognized prime minister, Ranil Wickremesinghe, is expected to be sworn in again as premier on Sunday, members of his and Mr. Sirisena’s inner circles said Friday night.