The official campaign period for the upcoming House of Councilors election will start on June 22, Liberal Democratic Party Secretary-General Toshimitsu Motegi said Saturday.

Motegi made the announcement during a meeting held in Yamanashi Prefecture, adding to growing expectations the Upper House election will be held July 10 if the current parliamentary session ends on June 15 as scheduled.

The schedule must be decided by the Cabinet of Prime Minister Fumio Kishida, who heads the LDP.

Motegi also said in a stump speech later in the day, "We have about 40 days left before the voting day."

Natsuo Yamaguchi, who heads Komeito, the LDP's junior coalition partner, told reporters in Saitama Prefecture, "We have been preparing for a July 10 election as a realistic option."

If the ongoing parliamentary session ends on schedule, and if the voting comes on a Sunday as usual, then the upcoming election will be set for July 10 based on election law.