Kyodo News Major television stations gave differing predictions Sunday on whether the three ruling parties would be able to secure a "stable" majority, meaning 254 of the 480 seats being contested at the House of Representatives.
They were also divided on whether the Liberal Democratic Party would be able to win a majority (241 seats) on its own.
For the main opposition Democratic Party of Japan, TV commentators were predicting significant gains from the 95 seats the party held prior to the election.
The tripartite coalition of the LDP, the New Komeito and the New Conservative Party, are likely to get a combined total of between 239 and 286 seats, NHK said.
TV Asahi predicted 272 seats, while Nippon Television Network Corp. (NTV) saw 266 seats.
NHK said the LDP alone is likely to take between 218 and 241 seats, TV Asahi said 236, and NTV predicted 235.
For the DPJ, NHK predicted 135 to 154 seats, TV Asahi 133 and NTV 142. NHK said the Japanese Communist Party will get between 15 and 24 seats, TV Asahi 20 and NTV 21.
The ruling camp has targeted a stable majority of 254, which would give it at least the same number of seats as the opposition in all Lower House standing committees, while chairing all of them.
LDP Secretary General Hiromu Nonaka, the party's No. 2 man, has set the goal at 229 seats for the LDP alone.
If votes fall short of the two targets for the LDP and the coalition, Prime Minister Yoshiro Mori could be forced to step down.
Prior to the dissolution of the Lower House on June 2, the coalition held 336 seats, 271 of which were held by the LDP.
The television stations compiled the survey based on interviews with 400,000 to 500,000 voters each at polling stations across Japan.
The stations unveiled the predictions immediately after voting ended at 8 p.m.