Official campaigns for an Upper House by-election in Oita Prefecture began Thursday, one of several electoral tests facing Prime Minister Fumio Kishida later this month as he tries to address the unpopularity of his government.

The start of the Oita race will be followed by the kickoff of campaigning for four Lower House by-elections next Tuesday. The five by-elections will be held on April 23, along with the second round of local polls to select mayors and assembly members across Japan.

Media polls show that the support rate for the Cabinet has picked up recently, especially since Kishida made a surprise visit to Ukraine — under invasion by Russia for a year — on March 21 for talks with Ukrainian President Volodymyr Zelenskyy.