By Linda Sieg
TOKYO (Reuters) - The Japanese government began a final push on Friday to enact contentious defense legislation that could let its troops fight overseas for the first time since World War Two, despite public protests and delaying tactics by the opposition.
Prime Minister Shinzo Abe says the policy shift, which would mark the biggest change in defense policy since the creation of Japan's post-war military in 1954, is vital to meet new challenges such as from a rising China.
Japan's ally the United States has welcomed the shift but the bills have sparked massive protests from ordinary citizens and other critics who say they violate the pacifist constitution and could ensnare Japan in U.S.-led conflicts.
Parliament's current session runs until Sept. 27, but ruling party lawmakers are keen to have the upper house approve the bills - the last step to enactment - before a five-day holiday starts on Saturday, when big street demonstrations could erupt.
Abe's ruling coalition has an upper house majority, but major opposition parties have pledged to halt a vote by submitting a string of censure motions in the chamber and a no-confidence motion in the lower house.
The opposition Democratic Party of Japan has not ruled out resorting to the "Ox Walk" tactic, where lawmakers walk at an excruciatingly slow pace to the ballot box, to delay the vote.
The bills, which include legal revisions to drop a long-standing ban on collective self-defense, or defending a friendly country under attack, were approved on Thursday by an upper house panel in a chaotic, raucous session.
Thousands of demonstrators have rallied near parliament every day this week, chanting "Scrap the war bills" and "Abe resign", and were set to gather again on Friday.
The protests have called to mind those that forced Abe's grandfather, Nobusuke Kishi, to resign 55 years ago after forcing a U.S.-Japan security treaty through parliament.
Besides ending the ban on collective self-defense in cases where Japan faces a "threat to its survival", the measures expand the scope for logistics support for the militaries of the United States and others, and for participation in peacekeeping.
The revisions will still leave Japan constrained in overseas military operations by legal limits and a deeply rooted public anti-war mindset.
Critics, however, say the changes make a mockery of the pacifist constitution and deplore what they see as Abe's authoritarian mode of pushing for enactment of the bills.
"They are using democratic institutions and processes, but the way he (Abe) uses them is not terribly democratic," said Keio University professor Yoshihide Soeya.
(Editing by Paul Tait)