Pressure mounted on embattled economy minister Akira Amari on Friday over allegations that he took cash for favors, as opposition lawmakers mounted a humiliating boycott of his annual policy speech in the Diet.

When Amari took the podium to unveil the year's economic program, lawmakers from the Democratic Party of Japan, Social Democratic Party, Japan Communist Party and Ishin no To (Japan Innovation Party) stood up and walked out.

The allegations against Amari are potentially damaging to Prime Minister Shinzo Abe's administration, in which Amari is a central pillar. He is also known worldwide as Japan's hard-nosed negotiator in the to and fro over the Trans-Pacific Partnership.