Japan's economy recently struggled out of its worst recession in decades, expanding at an annual pace of 3.7 per cent in the second quarter.
But economists note that exports served as the main driver of growth and that domestic demand remains fragile with many companies continuing to slash their payroll.
The latest jobless figures come just two days before national elections that are being seen as a referendum on the LDP's handling of the economy.
Recent polls predict that Aso's ruling party, in power for most of the last half-century, is on course for a landslide defeat to the opposition Democratic Party of Japan (DPJ).
Under a mantra of "Putting People's Lives First" the DPJ, led by Yukio Hatoyama, are offering a platform heavy on social welfare initiatives, including cash handouts for job seekers in training and families with children.
Analysts say that message has appealed particularly to Japan's youth, who could play a crucial role in the upcoming vote.
Tobias Harris, a political commentator and blogger based in Tokyo, said many young Japanese felt "a tremendous disappointment and anger at LDP rule."
"They're feeling the burden of the economic downturn particularly heavily and like most Japanese people they see that the government hasn’t really done anything for them," he told Al Jazeera.
Record high support
On Friday a pre-election poll in the Mainichi newspaper poll showed public support for the DPJ at a record high, with 39 per cent of respondents backing the party.
Support for the LDP in contrast stood at just 20 per cent.
The Mainichi poll is the latest in a raft of voter surveys pointing to an expected rout of the LDP.
|Yukio Hatoyama is campaigning on a platform of change [AFP]
A poll of more than 130,000 voters in the Asahi newspaper earlier this week said the DPJ could take as many as 320 seats in the 480-seat lower chamber of the Japanese parliament, leaving the LDP with as few as 100 seats.
However the paper warned that the situation could change, with nearly 40 per cent of respondents saying they were undecided or declining to say which party they would vote for in 300 single-seat constituencies.
On the campaign trial on Thursday, Taro Aso admitted voters were unhappy with his party's performance.
"I think criticism has been building", the embattled premier said while campaigning in the western city of Osaka, Jiji Press news agency reported.
"We have failed to make clear the virtues of conservatism… We regret we haven't sent a clear message in the past few years."