Idukki: The Idukki district secretary of the Communist Party of India (Marxist) has been heard saying in a video that Congress state chief K Sudhakaran owes his life to his party.

"Sudhakaran's life is CPM's favour. We have no intention to kill a wretched creature," C V Varghese, the CPM leader, threatened in a video that has come out in the public realm.

The CPM district secretary delivered the controversial speech at Cheruthoni, reports say.

The ties between CPM and Congress have been tense in Idukki district ever since an engineering student belonging to the Students' Federation of India was stabbed to death by a Youth Congress activist. Sudhakaran had defended the accused.

Sudhakaran, the president of Kerala Pradesh Congress Committee (KPCC), is known for his aggressive style. For decades he has been a thorn in the flesh of the Marxist party and has almost single-handedly challenged the Marxists in their stronghold in Kannur.

Last year Sudhakaran had crossed swords with Marxist veteran and Kerala Chief Minister Pinarayi Vijayan by raking up conflicts during their student days.

Soon after he had taken over as the KPCC chief, Sudhakaran claimed that during his college days he had knocked down Pinarayi Vijayan at the Government Brennen College in Thalassery. Vijayan had responded in kind and boasted about how he had spared Sudhakaran back then.