"PM called VS and congratulated him for the LDF victory," a close aide of the senior leader told PTI.
The Prime Minister also tweeted, "Spoke to V S Achuthanandan ji & wished him on his victory & his Party's impressive performance in the elections."
Achutanandan had travelled the length and breadth of the state during the campaign for the May 16 Assembly polls, defying his advanced age. He contested from Malampuzha and won by a margin of 27,142 votes.