TOKYO (Reuters) - The Bank of Japan should wait for at least six months before hiking interest rates, until there are signs of sustainable wage gains above inflation, the head of the opposition party that the ruling LDP is courting for support said.

"We need to keep a close watch on what is happening with wages," Yuichiro Tamaki, head of the opposition Democratic Party for the People (DPP), said in an interview.

The LDP, along with its coalition partner Komeito, are 18 seats short of a majority in the 465-member chamber after the Oct 27 general election, meaning they need the support of at least one other political party to stay in power.

Tamaki's party, which is in cooperation talks with the LDP, saw its seat count in the lower house jump to 28 from seven on a platform calling for a cut to the country's sales tax, income tax and an increase in welfare benefits.

(Reporting by Makiko Yamazaki, Takaya Yamaguchi, Tim Kelly, Philippa Fletcher)