Japan’s opposition-controlled upper house passed a censure motion yesterday against Prime Minister Yoshihiko Noda, piling more pressure on him to make good on the promise to call an early election “soon”.

The reprimand is non-binding but effectively means that the opposition will stop cooperating with the government on most Bills, including key ones on deficit financing and voting reform that need opposition votes to pass.

The motion passed easily, with 129 votes in favour and 91 against. Jeers rang out in the chamber as members derided the Prime Minister’s foreign policy and demanded to know when he would call the election. Mr Noda promised this month to call an election to Parliament’s lower house as the price for opposition support for his plan to raise the sales tax to offset rising social security costs.

But to the growing frustration of his rivals, he has since been coy on the timing of the vote and last week brushed off as speculation reports that he had suggested a November date in his talks with opposition leaders.

No one expects the Parliament to serve its full term that ends in August 2013 but many of Noda’s Democrats want to push back the vote as opinion polls show they would lose badly.

By threatening to stall the Bill that the government needs to cover the bulk of its fiscal deficit and 40 per cent of all spending, the opposition hopes to finally win his unequivocal commitment.

Five months into this fiscal year, the government has made do by dipping into reserves and making other adjustments. But Finance Minister Jun Azumi has warned the government could run out of cash by early October if the Bill fails to pass.

In its censure motion that it later merged with one submitted by smaller parties, the main opposition Liberal Democratic Party accused Mr Noda and his government of in-competence in handling state matters.