Japanese Prime Minister Shinzo Abe attends a press conference in Tokyo, Japan, on Sept. 25, 2017. (Xinhua)

TOKYO, Sept. 28 (Xinhua) -- Japanese Prime Minister Shinzo Abe on Thursday dissolved the more powerful lower chamber of Japan's bicameral parliament and called a general election.

The general election will be held on Oct. 22, with official campaigning set to start on Oct. 10.

Abe dissolved the lower house as soon as it convened at noon (local time) for an extraordinary session.

Much to the chagrin of opposition parties, Abe made no policy speech, shirked any parliamentary debate and held no press conference afterwards.

The overall timing of the dissolution and calling of a snap election, observers have said, is to not allow the opposition camp enough time to fully prepare for the upcoming general election.

However, Tokyo Gov. Yuriko Koike's newly-formed Party of Hope may see an effective merger with the main opposition Democratic Party to better stand against the ruling Liberal Democratic Party-led (LDP) bloc in the upcoming campaign.

Democratic Party leader Seiji Maehara, just three weeks into his tenure, has had to contend with disunity and defections from his party, but has intimated that his party may also join forces with the minor opposition Liberal Party, headed by political heavyweight Ichiro Ozawa.

Abe said Monday that the dissolution of the house and calling of a snap election is in essence to seek a mandate on his ways to address Japan's rapidly aging society, falling birth rate and issues of security related to tensions on the Korean Peninsula.

The prime minister recently unveiled a 2 trillion yen (17.8 billion U.S. dollars) policy package to be paid for by an allocation of revenue generated from 2019's consumption tax hike, to service social welfare costs.

Abe last dissolved the lower house of parliament in November 2014 and thereafter led the LDP and its junior Komeito coalition ally to a sweeping victory in the following election in December.

Thursday's dissolution marks the 4th time in postwar Japan that the lower chamber has been dissolved on the day the Diet has convened.

The Japanese leader could theoretically serve until 2021 if he is reelected as party leader next year.

This would make him the longest-serving prime minister in Japanese history.

Recent polls, however, have shown that the majority of voters are opposed to this idea.

Since the recent shake up in national politics, Abe has, of late, been muted on his contentious plans to amend Japan's pacifist constitution following a national referendum.