Voter support for Japanese Prime Minister Yoshihiko Noda's government dropped for a third straight month, a survey showed on Sunday, with a majority demanding a general election before parliament passes a bill to double the 5 percent sales tax.

This adds to Noda's headaches as he faces mounting calls within and outside his ruling party for the defence minister to quit over gaffes.

Only a quarter of those surveyed backed Noda's plan to call an election after passing the contentious bill and before raising the tax. The general election must be held by late 2013.

Support for Noda, who took office in September vowing to fix tattered finances and steer Japan's recovery from the March earthquake, slid to 44.6 percent from 47.1 percent in the previous month, according to the survey by Kyodo news agency.

The government is aiming to decide on the timing and scale of the politically sensitive sales tax hike this month before submitting a relevant bill to parliament before the current fiscal year ends in March.

Noda is struggling to win broad support for the sales tax plan even as Europe's debt crisis sounded an alarm bell for Japan's heavily-indebted government.

In the same survey, 82 percent supported other tax increases planned by the government to finance post-quake reconstruction efforts.

Debate on raising the sales tax, one of the lowest among major economies, has long been politically touchy. The last consumption tax increase, in 1997, was blamed by some for triggering a recession that led to a long period of deflation.

Highlighting public distrust against politics, 71.5 percent called for a realignment of political parties, Kyodo said.

(Reporting by Tetsushi Kajimoto; Editing by Yoko Nishikawa)