The Congress-led UDF Friday took early lead in 13 of the 20 seats as officials counted the millions of votes polled in the Lok Sabha election.
The LDF led by the CPI-M was ahead in seven seats, officials said.
LDF candidates were forging ahead in Kannur, Vadakara, Attingal, Alalthur, Mavelikera, Thrissur and Chalakudy constituencies, and the UDF in Thiruvananthapuram, Alappuzha, Kottayam, Kasargode, Kozhikode, Ponnani, Ernakulam, Malappuram, Palakad, Idukki, Kollam, Idukki and Pathanamthitta.
In 2009, the UDF won 16 and the LDF four Lok Sabha seats.