As Prime Minister Yoshihide Suga prepares for the start of an extraordinary Diet session, set to open Monday, he also has to contend with the growing question of when he will call an election.

Suga’s tenure as Liberal Democratic Party (LDP) president will end next September and the terms of Lower House lawmakers will expire the following month, leaving Suga with limited wiggle room to form a strategy on dissolving the Lower House.

Calling an election at the right moment has been always an arduous task for prime ministers. For Suga, who was appointed to the role just a month ago, it is an important test of his acumen as a politician and, depending on the outcome, could embolden or weaken his standing within the ruling party.