Official campaigning began Thursday for the House of Councilors elections, where some 480 candidates will compete for half of the 252 seats up for grabs in the Upper House.
The July 12 poll is widely expected to be a major confidence test for the government of Prime Minister Ryutaro Hashimoto, which is being heavily criticized its inability to bring the economy out of recession.
The election's main focus will be the Liberal Democratic Party's attempts at taking a majority in the Upper House. The LDP holds 118 seats in the chamber, with 60 of them up for grabs. If successful, it would be the first time since 1989 the ruling party has had majority control.
The major issue is the economy, specifically how to reinvigorate it. For its part, the LDP is touting a 16.65 trillion yen stimulus package. Opposition parties are promising major tax cuts and accusing the Hashimoto administration of failing to implement proper economic policies.
The LDP must secure 69 seats to cinch a majority.
Although an LDP setback will not require a change of government, analysts say it would affect such things as the timing of a Cabinet reshuffle by Hashimoto.