Updated

Japanese Prime Minister Naoto Kan, criticized for his handling of the tsunami disaster and the country's sluggish economy, is under pressure to resign next month after budget bills are passed by parliament, reports said Monday.

Kan is being pushed by senior members of his party to step down after the passage of a second extra budget for the current fiscal year, which ends in March 2012, according to the Kyodo News agency and public broadcaster NHK.

Passage is expected in mid-July.

Kyodo and NHK said Kan is expected to announce details of his intentions soon, after meeting with the party leadership. NHK said it is not clear whether he will agree to step down next month or try to hold on longer.

Kan has said he is willing to resign after the country's recovery from the disaster takes hold, but has not specified when.

No clear successor has pulled away from a pack of potential replacements, though the Japanese media have focused on Finance Minister Yoshihiko Noda, a fiscal expert who shares many of Kan's policies.

Kan's resignation would be an embarrassment to his ruling Democratic Party of Japan, but his rivals in the party apparently believe it would be better off without him at the helm.

Kan has been under increasing pressure to resign because of his perceived lack of leadership following the March 11 earthquake and tsunami that devastated the country's northern coastline and left about 23,000 people dead or missing.

Damage is estimated at $300 billion, making it the most expensive natural disaster in history.

He has also been hammered for his handling of the crisis at the Fukushima Dai-ichi nuclear plant, which was severely damaged by the tsunami.

But Kan was deeply unpopular even before the disasters as he struggled to find policies to boost the economy, lower unemployment and deal with the public debt.

Kan assumed office just over a year ago. Japan has had five prime ministers in the past four years, and its parliament is mired in gridlock.

The disasters have been a major test for Kan.

Factories throughout the region were damaged, leading to shortages of parts and components for automakers and other manufacturers. Consumer spending has plunged and the crippled nuclear power plant has caused widespread power shortages that could worsen in the months ahead.

Last week, the International Monetary Fund slashed its outlook for Japan, predicting its economy will shrink 0.7 percent this year instead of growing 1.4 percent.