Prime Minister Shinzo Abe's snap election gamble looked like it was paying off after a Kyodo News poll forecast a big win for the ruling bloc, with a margin of victory possibly enough to re-energize his push to revise the post-World War II pacifist Constitution.

A hefty victory in the Oct. 22 poll would raise the likelihood that his Liberal Democratic Party will retain Abe as its head for a third term next September, and increase the hawkish leader's chances of going on to become the longest-serving prime minister.

With 9 days to go until the Lower House election, political sources warned there is still room for a slip up, as about half the voters in the survey remained undecided.