The following year he successfully unseated George de Silva in an election petition that striped him of his civic rights and contested the by-election in the Kandy electorate as an independent socialist candidate defeating de Silva's son Fredrick de Silva, he entered the House of Representatives of Ceylon and was sworn in on 18 May 1948. He soon had to step down due to an election petition that striped him of his civic rights and in the by-election that followed, his wife Tamara Ilangaratne contested and won the Kandy electorate in June 1949. Joining S. W. R. D. Bandaranaike in his newly formed Sri Lanka Freedom Party, Ilangaratne contested the 1956 general election from Galaha and re-entered to the House of Representatives in the landslide victory the Sri Lanka Freedom Party gained defeating Theodore Braybrooke Panabokke.
In 1949, he successfully challenged George de Silva's seat through an election petition that revoked his voting rights, and then ran as an independent socialist candidate in the by-election, beating de Silva's son Fredrick. He entered Parliament on May 18, 1948, but was forced to resign due to another election petition that stripped him of his rights. His wife Tamara won the Kandy seat in June 1949. Ilangaratne joined S. W. R. D. Bandaranaike's Sri Lanka Freedom Party and won a seat from Galaha in the 1956 general election, helping the party secure a landslide victory.