Japan's ruling party power broker Ichiro Ozawa is ready to challenge Prime Minister Naoto Kan, adding to the pressure on the unpopular leader as he struggles with the nuclear crisis, the Wall Street Journal reported on Friday.

I am thinking about how to deal with it right now, Ozawa told the newspaper when asked if the opposition party had any plans to support a no-confidence motion against Kan. He also said that there was a growing anxiety and frustration among the people over government's negligent response to the post earth quake-tsunami nuclear crisis which devastatingly hit Japan on March 11.

Japan's biggest opposition party plans to submit a no-confidence motion to parliament, its leader Sadakazu Tanigaki said on Thursday. The motion would require support from 75 out of the 300 ruling Democratic Party of Japan lawmakers and it is not clear how many of them would be prepared to do so, forcing Kan either to resign or call a snap poll.

Ozawa was accused of an alleged violation of campaign-funding laws this year. A seasoned political strategist who was once the head of the ruling party and who last year challenged Kan in a party leadership contest, said I was thinking about just fading away but now I feel I have a bit more work to do, adding that he believed Kan should go.

If the prime minister cannot implement policies, it's meaningless for him to stay in power. I think the sooner he's replaced the better, he said

He has stayed in the party despite Kan's request to distance himself until his trial is over, the report said.