Kan, whose support ratings have sunk to about 20 percent, has already been facing pressure from inside and outside his Democratic Party (DPJ) either to quit or call a snap election to break a political deadlock that is keeping Japan from dealing with pressing problems including a massive public debt.

“We need to put top priority on the passage of the budget and related bills over the DPJ or Prime Minister Kan,” Kozo Watanabe, a supreme adviser to the DPJ, told reporters in televised comments. But he added that as long as Kan wanted to stay on, it was party members’ duty to “protect” him.

Rifts in Kan’s own party, which deepened after powerbroker Ichiro Ozawa was indicted over funding scandals last month, have also weakened the premier’s grip on power and distracted the government from dealing with policy problems.

Speaking on a nationwide television program earlier in the day, Watanabe, a veteran lawmaker, ruled out the chance of a snap election for the parliament’s powerful lower house as the DPJ would be defeated at the polls, Kyodo news agency said.

Sounding a theme he has raised before, Shizuka Kamei, the head of a small coalition party, the People’s New Party, called for a cabinet reshuffle that would bring in opposition lawmakers as a way to break the political impasse, public broadcaster NHK reported.

“Prime Minister Kan must forget the past, forge ahead and stand at the forefront of such a choice,” Kamei told reporters.

But DPJ Secretary General Katsuya Okada dismissed talk of Kan’s resignation in return for opposition help with passing bills, including one to allow the issuance of deficit-financing bonds to carry out steps in the budget for the year starting in April.

“The opposition has rejected the idea of such an exchange so to focus on that debate is meaningless,” Okada told reporters.

Analysts have suggested, however, that the second-biggest opposition party, the New Komeito, may turn amenable to a deal after nationwide local elections in April are over.

The government wants to have parliament’s lower house, where the DPJ holds a big majority, approve the $1 trillion 2011/12 budget on Monday, but plans to hold off on submitting related bills.

The budget itself can be enacted by parliament’s lower house alone. But the related bills to implement the budget require approval of the opposition-controlled upper chamber.