New Japan PM's tenure may be short-lived if he makes a misstep

He will have to walk a tightrope between balancing party interests and public opinion

- Walter Sim

The stars have finally aligned for Mr Shigeru Ishiba, a man once branded a “traitor” for having at one time quit the ruling Liberal Democratic Party (LDP) and whose leadership ambitions were written off as he publicly feuded with kingmakers.

He pulled off a come-from-behind victory on Sept 27 to prevail in his fifth attempt at the top job, and will be sworn in as Japan's prime minister on Oct 1, with his Cabinet to be named the same day.

The 67-year-old benefited from circumstance. Party factions, along whose lines MPs used to vote, have mostly been relegated to history. Meanwhile, amid the LDP's most damaging scandal in years - involving a political slush fund that implicated one in five MPs - lawmakers may bank on his status as a maverick outsider to win over an incensed public.

But political observers see his position as wobbly, and believe he could be the latest in a line of revolving door prime ministers if he were to make a misstep. While the LDP will likely put up a show of unity in the wake of its most bruising party presidential election in years, with a record nine candidates in the running, Sophia University political scientist Koichi Nakano told The Sunday Times that the party could descend into "civil war".

With Mr Ishiba having received 189 votes from lawmakers in the run-off, his thin margin of victory over runner-up Sanae Takaichi - the 63-year-old conservative economic security minister who received 173 votes - shows “the degree to which the party is internally divided”, said Dr Nakano.