EXPLAINER-Next steps to confirm Takaichi as Japan's new prime minister

For most of the post-war period, the pick for LDP president was a shoo-in for the premiership because it held the majority in parliament, either on its own or with a coalition partner.

The LDP-led coalition lost its majority in both houses of parliament in elections over the past year, but the party remains the biggest in the more powerful lower chamber, meaning Takaichi's chances of becoming the premier are almost certain.

Lawmakers are expected to choose the new prime minister in mid-October.

PARLIAMENT VOTES

Based on precedent, the more powerful lower house will first vote on its choice for prime minister, followed by the upper house. Lawmakers can nominate any candidates from the chamber, and historically the leaders of opposition parties have been put forward for the vote.

Any candidate who secures a simple majority in the first round wins approval. If no one secures a majority, a run-off poll follows, between the two candidates with the most votes.

If there is a disagreement between the houses, the choice of the lower house prevails. This happened in 2008 when the lower house chose the LDP candidate and the upper house picked an opposition candidate.

In 1994, the LDP formed a three-way alliance with its arch-rival, the Japan Socialist Party, and a smaller startup party to regain power, having socialist leader Tomiichi Murayama elected as prime minister.

NEXT STEPS

Once the premier is chosen, incumbent Shigeru Ishiba will step down, Takaichi will select her cabinet members and the new line-up will go to meet the emperor to formalise the formation of the new government.