Japan's upper house, which is controlled by the opposition camp, voted on Friday to censure two ministers in Prime Minister Yoshihiko Noda's cabinet, media reported.

Censure motions against Defense Minister Naoki Tanaka and Transport Minister Takeshi Maeda were approved by a majority at the plenary session of the House of Councilors.

The main opposition Liberal Democratic Party vowed to boycott parliamentary discussions unless the two censured ministers are replaced. But the government and the ruling party decided to support the two officials.

The motions are non-binding but could overshadow the interparty talks on a consumption tax hike proposed by the ruling Democratic Party, analysts said.

The ruling Democratic Party of Japan (DPJ) aims to tackle the country's ballooning social security costs by raising the current 5 percent consumption tax in two stages, to 8 percent in 2014 and to 10 percent in 2015.

In order to get the controversial tax hike bill passed, Noda needs the support from the opposition camp, which so far has refused to collaborate.

Tanaka was under fire for a string of remarks that the opposition said suggested his poor handling of security issues, while Maeda came under attack for allegedly interfering in a recent local election.