Prime Minister Yoshihiko Noda and Democratic Party of Japan executives officially endorsed changes to the government's social security and tax reform bills Wednesday, while signalling the Diet session will be extended, possibly to early September.

Noda was forced to postpone a vote on the revised bills in the Lower House beyond Thursday's scheduled end of the Diet session, given the fierce opposition from DPJ members against the planned consumption tax hike.

The prime minister had been keen on having the contentious tax hike bill approved before Thursday, but with that bill and other key legislation still hanging fire, the DPJ proposed extending the session to Sept. 8 in a meeting with opposition parties, which didn't give an immediate answer, party sources said.