Prime Minister Naoto Kan on Thursday admitted his push to open debate on hiking the consumption tax cost his Democratic Party of Japan seats in the July 11 Upper House election but called on his colleagues to support his Cabinet and unite for the tough road ahead.

"I apologize from my heart for my careless remarks, which became a cause for a difficult election campaign," Kan said at a meeting for all DPJ members in the Diet. "But we must now pull together as a team in order to promulgate our policies."

Kan also expressed his eagerness to remain as leader of the DPJ while facing pressure from his ranks to step down over the ruling bloc's loss of its Upper House majority. If he exited before September, this would set the stage for a fourth prime minister within a year's time.