In protest of remarks made by Agriculture, Forestry and Fisheries Minister Yuji Yamamoto on Tuesday suggesting the ruling parties could steamroll approval of the Trans-Pacific Partnership free trade pact through the Diet, lawmakers belonging to the two largest opposition parties walked out before Diet deliberations began on Friday.

However, the ruling parties continued on their own with the unsworn testimony session in a special House of Representatives committee on the TPP deal, which Japan and the United States inked with 10 other Pacific Rim nations in February.

Lawmakers from the Democratic Party and Japanese Communist Party sat out the session, in which the ruling parties quizzed several university professors on agricultural issues, after unsuccessfully urging committee head Ryu Shionoya to call it off.