By Linda Sieg and Nobuhiro Kubo
TOKYO, June 10 (Reuters) - Japanese Prime Minister Shinzo Abe's campaign to ease constitutional curbs that have kept the military out of overseas conflicts for nearly 70 years is going down to the wire.
With less than two weeks before a self-imposed deadline, a gulf yawns between the hawkish leader and his dovish coalition partner on changes that would allow Japan's military to go to the aid of a friendly nation under attack.
The stalemate has sparked speculation that Abe might call a snap poll to seek a mandate to lift the ban on so-called collective self-defence, though sceptics say an election would distract from efforts to revive the economy, a top priority since Abe took office in December 2012.
Abe has made clear he wants his cabinet to adopt a resolution to let Japanese forces engage in combat overseas, which has been ruled out under a decades-old interpretation of the post-World War Two, U.S.-drafted pacifist constitution.
The United States and some Southeast Asian countries would welcome the change, while rival China would almost certainly criticise it as further evidence that Tokyo, rather than Beijing, is ramping up regional security tension.
But the ruling Liberal Democratic Party's (LDP) junior coalition partner, the New Komeito, and the lay Buddhist group that backs it, are wary of signing off on what would be a major shift in Japan's security policies.
"At present, we can't say that the gaps between the LDP and New Komeito have narrowed," LDP Vice President Masahiko Komura told reporters after inter-party talks on Tuesday.
If a draft cabinet resolution is not presented at the next round of talks on Friday, the schedule would be too tight for it to be adopted during parliament's current session, he said.
Abe, who has long fretted under the restraints of the U.S.-drafted constitution, wants the cabinet to adopt the change before parliament breaks on June 22.
That would allow it to be reflected in an update of U.S.-Japan defence cooperation guidelines the allies aim to complete by the end of the year.
Abe and his aides fear that if the talks drag on, momentum for the change, which many voters oppose for fear Japan would be drawn into overseas wars, will be lost.
Critics say the re-interpretation of the constitution would gut its war-renouncing Article 9 and bypass politically tough amendment steps. Advocates say growing regional threats, including from an increasingly assertive China, mean Japan cannot afford to wait.
Sino-Japanese ties have been strained by a feud over tiny isles in the East China Sea, distrust of each other's defence policies, and rows stemming from the legacy of Japan's wartime occupation of much of China.
"Overdue homework should be done in a hurry because the possibility of a clear and present potential threat is increasing," said former Japanese diplomat Kunihiko Miyake.
"The longer it takes, the less furious debate will be. We have to strike while the iron is hot."
If Abe were to call a snap election for parliament's lower house, as some media has speculated, he could cast victory as public backing for his security stance.
"All options are conceivable ... If support rates were low, he wouldn't do it, but now support rates are high, so it wouldn't be a problem," LDP General Council head Seiko Noda told Reuters. "But this is something only the prime minister knows, Clock ticks as Japan PM pushes to loosen constraints on military so I can't comment."
A survey by the NHK public broadcaster released on Monday put support for Abe's cabinet at 52 percent, down four points from a May poll. Forty-one percent were undecided about collective self-defence, while those in favour and those opposed accounted for 26 percent each.
At 36.9 percent, backing for Abe's LDP dwarfed the 5.1 percent who supported the main opposition Democratic Party, but 42.4 percent supported no particular party.
Political experts said, however, that chatter about a snap election was more likely a tactic aimed at getting the New Komeito to compromise.
The LDP has a clear majority in parliament's lower house, but needs the New Komeito's support to pass bills in the upper chamber, which can block legislation. Support from the lay Buddhist Soka Gakkai group which backs the smaller party is also critical for many LDP lawmakers to keep their seats.
"The New Komeito has a final card to play - refusing to cooperate with the LDP in an election," said Tomoaki Iwai, a political science professor at Nihon University. "The possibility (of a snap election) is not zero, but it is not very realistic." The next general election must be held by 2016. (Editing by Robert Birsel)