The Left Democratic Front on Tuesday retained the Thiruvananthapuram Lok Sabha seat, with the Communist Party of India's Pannyan Raveendran defeating his Congress rival V S Sivakumar by a margin of over 70,000 votes in the by-election.

In the grimly fought by-election, held barely six months before the completion of the term of Congress-led United Democratic Front government, the fledgling Democratic Indira Congress, led by veteran K Karunakaran, had pledged its total support to the LDF.