Two main opposition parties on Monday spurned a call by the ruling Democratic Party of Japan to hold talks on social security and tax reform, dealing another setback to Prime Minister Yoshihiko Noda as he seeks support for a contentious tax hike bill.

The Liberal Democratic Party and New Komeito turned down an official request by DPJ Diet Affairs Chief Koriki Jojima in the morning to start talks on Tuesday.

"The timing (to hold leaders' talks) is too bizarre since we're expected to hold (one-on-one) debate sessions by party leaders at the Diet on Wednesday," LDP Diet member Fumio Kisida told the press after meeting with Jojima.

Desperate for opposition support in the divided Diet — the opposition controls the Upper House — Noda was hoping for a breakthrough with a direct appeal for cooperation from the LDP and New Komeito to pass the tax hike bill, which would double the 5 percent sales tax by 2015.

Noda said recently he wants the Diet to start deliberations on the bill by the end of April, aiming for passage during the current Diet session, due to end on June 25.

Noda had also hoped party leaders could address other issues, including a special bill on issuing deficit-covering bonds to finance as much as 40 percent of the fiscal 2012 budget, revising the civil servant system to give them the right to collective bargaining, and establishing a new nuclear regulatory agency.