Congress-led UDF is maintaining a slight edge over CPI(M)-led LDF by leading in 11 of the 20 seats in Kerala as counting trends came in.
In a fluctuating trend in Thiruvananthapuram, Union minister Shashi Tharoor and BJP's O Rajagopal are locked in tight fight in the first round of counting.
UDF, which won 16 seats in 2009, is leading in 11 seats while the LDF is ahead in nine constituencies in the first hour of the counting, according to election officials.
Leading UDF candidates include union minister K V Thomas (Ernakulam) and MI Shanawas (Wayanad).
Indian Union Muslim League all-India president E Ahamed (Malappuram) has established a comfortable lead of 13,000 votes over his LDF rival P K Sainaba in Malappuram.
His colleague E T Muhammad Basheer (Ponnani) is also leading.
Union minister Mullappaly Ramchandran lags behind CPI-M's A N Shamseer by about 300 votes in Vatakara.
Congress leader P C Chacko is behind actor Innocent of LDF by about 3000 votes in Chalakkudi.
The LDF candidates who are ahead include P K Sreemathy (Kannur), A Sampath (Attingal) and P K Biju (Alathur). CPI(M) leader M A Baby is lagging behind RSP's N K Premachandran in Kollam. BJP leader
O Rajagopal is leading by 695 votes in Thiruvananthapurm over Congress candidate Tharoor.
