Last week Mr Kan survived an opposition no-confidence motion that some members of his own party had threatened to support, after appeasing his enemies by promising to relinquish power but without specifying a date.
Mr Kan later hinted he wanted to stay until next year, angering opponents.
'His real thought is to get his work done by the end of August,' said Shizuka Kamei, leader of ruling coalition partner the People's New Party.
'That was the idea shared when I met him,' he told TV Asahi on Sunday.
The government is expected to submit its second extra budget to parliament in August. The budget is aimed at funding the government's reconstruction effort after the March 11 quake and tsunami disaster. -- AFP