Former Prime Minister Ranil Wickremesinghe was sworn in as a Member of Parliament before the Speaker just a few moment ago.
The National List seat has been vacant for more than 10 months since the last general election.
Ranil Wickremesinghe, who represented Sri Lanka in Parliament continuously from 1977 to 2020, was defeated in the 2020 election.
However, the UNP won only one National List seat in that election.