Japan's main opposition Liberal Democratic Party said Wednesday it would look at establishing a permanent presence on uninhabited Tokyo-controlled islands at the centre of a dispute with China.

The main opposition party also promised a review of the self-imposed ban on defending allies, offering the possibility of Japanese troops returning fire if US forces come under attack.

Promises to "examine" the issues were part of a series of policy pledges ahead of December 16 polls.

The document, presented by LDP leader Shinzo Abe, offered a number of "reviews" and "studies", but stopped short of promises of action with binding goals.

Opinion polls suggest the LDP could be the largest party after the election, putting Abe in line for a return to the premiership, but will need support from coalition partners to form a government.

The document said the party "will clarify the rights of self-defence, including collective self-defence, and then will legislate basic law on national security".

Collective self-defence refers to the right to take aggressive action when an ally is attacked, a right Japan already has, but has thus far refrained from using.

The country's pacifist stance enjoys widespread public support, despite its having been foisted on a defeated Japan by US occupiers after World War II.

The LDP, which ruled Japan for an almost unbroken half century before it was ousted in 2009 by the Democratic Party of Japan, said it would "study the stationing of public servants to protect" uninhabited, Tokyo-controlled islands at the centre of a territorial row with China.

"We will review policies on the Senkaku islands, which Japan has a policy of keeping unmanned despite the fact they are Japanese territory, so as to strengthen Japan's control over the islands," it said, referring to an archipelago known as the Diaoyus in Chinese.

The 54-page election booklet contains more aspirations than policy proposals, including on restoration from last year's tsunami disaster, on economic growth, social welfare and improvement in Japan's dismal fiscal position.

Party leaders say they want to achieve three percent nominal growth, prioritising polices to exit from years of deflation and a higher yen.

"Aggressive easing" and the quick implementation of fiscal stimulus were prescribed, but no timescale was given on when the growth would be achieved.