Japan's ruling party votes for a new leader on Wednesday who will almost certainly become the next prime minister ahead of a general election due in weeks and with the economy staggering from the Covid-19 pandemic.

Prime Minister Yoshihide Suga, his support in tatters ahead of the election, in a surprise move said he would step down after only a year as the Liberal Democratic Party (LDP) leader at a scheduled Sept 29 party vote.

The new party chief is expected to...