TOKYO, May 8 (Xinhua) -- Japan's major opposition parties conducted Diet sessions as normal on Tuesday, bringing an end to an 18-day boycott of proceedings to protest the government's mishandling of multiple cronyism scandals implicating Prime Minister Shinzo Abe.

The opposition camp is now gearing up to gain more clarification on the scandals and wants to cross-examine the government over its role involving protracted influencing-peddling scandals connected to two educational institutions, the Finance Ministry and other individuals.

It was agreed on Monday between both ruling and opposition parties that Tadao Yanase, a former aide of Abe's, would be summoned to the Diet as an unsworn witness to give testimony on details pertaining to the opening of a veterinary school in a specially deregulated zone in Ehime Prefecture.

The veterinary school, which opened last month, is operated by Kake Educational Institution, which is run by Kotaro Kake, a close friend of Abe's.

Yanase, now vice minister for international affairs at the Ministry of Economy, Trade and Industry, is believed to have used the influence of the prime minister's office to ensure the plans for the new veterinary school were prioritized.

He is alleged to have said the setting up of the veterinary department was a "matter concerning the prime minister."

Abe, however, has repeatedly denied allegations that he used his influence to ensure the government's approval for the opening of the veterinary school, the first of its kind to be opened in half a century in Japan.

The parliamentary boycott was triggered by the government not allowing Yanase and others related to the cronyism cases and other scandals, such as the Finance Ministry tampering with key evidential documents related to the case, to be summoned to the Diet.

Prior testimony saw Yanase saying he had no memory of meeting local officials from Ehime Prefecture regarding the opening of the veterinary school, despite evidence to the contrary.

He will now, during his upcoming testimony, retract his remark and is expected to admit that the meeting did take place at the prime minister's office in Tokyo on April 2, 2015.

Sources close to the matter said that Yanase would maintain that he did not refer to the Kake project as a "matter concerning the prime minister."

Abe himself, next week, will attend sessions in both chambers of parliament, during which the opposition camp will grill him over the Kake scandal and others, including those related to the sale of a piece of state-owned land to a nationalist school operator with ties to Abe's wife, for a fraction of its appraisal value.