A decision in this regard was taken at a meeting of Front leaders here, Front Convener P P Thankachan told reporters here.
Earlier the AIFB had unsuccessfully tried to gain entry into CPI(M) led LDF in Kerala.
AIFB National Secretary G Devarajan welcomed the UDF decision and said it would strengthen secular and democratic forces at the national level.
"LDF lead partner CPI(M) has failed to read the writing on the wall with the changing times" he said.
AIFB will play its small role to strengthen UDF in Kerala, he added.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)