The Democratic Party of Japan said Thursday that 33 of its 244 Diet lawmakers did not pay mandatory premiums for the nation's basic pension system, leaving the Liberal Democratic Party as the only major party still refusing to disclose the payment records of its members.

Fuel was added to the fire as seven LDP members, including two senior vice ministers of the Health, Labor and Welfare Ministry and Ichiro Aisawa, senior vice foreign minister, said the same day they are on the ever-growing list of politicians who have missed premium payments.

Five DPJ members who chaired committees in the House of Representatives and the House of Councilors resigned those posts earlier in the day to take responsibility for missing payments, in what was seen as a political move to contain damage and exert more pressure on the LDP.