Japanese Prime Minister Naoto Kan has rejected calls for his resignation, after opposition parties tabled a motion of no-confidence against him.The motion criticises Mr Kan for his response to the tsunami and earthquake in March and the continuing radiation leaks at the Fukushima nuclear power plant. If Mr Kan loses the vote of confidence, he will be forced to resign or call an election.Reports say key members of his Democratic Party may vote against him. Mr Kan's main rival within the party, Ichiro Ozawa, said he will support the move against the Prime Minister as did former premier Yukio Hatoyama.The no-confidence motion was submitted by the main opposition Liberal Democratic Party (LDP), their smaller ally the New Komeito Party and the Sunrise Party and is expected to be backed by the Communist Party.The LDP has accused Mr Kan of mishandling the reconstruction and relief efforts following the tsunami, as well as the Fukushima nuclear crisis.