Opposition parties stepped up calls Thursday for Prime Minister Shinzo Abe's wife, Akie, to be summoned to testify in the Diet, after the head of a nationalist school operator reiterated under oath in the Diet earlier in the day that Akie Abe had handed over a donation for the organization on the prime minister's behalf.

The ruling camp led by Abe's Liberal Democratic Party dismissed the claim by Yasunori Kagoike, which was previously denied by Abe's wife.

"The curtain did not close on the problem (with Kagoike's testimony in the Diet), but rather just opened," Democratic Party leader Renho said in a press conference, emphasizing the main opposition party's resolve to pursue Abe over the scandal.