Major party leaders held their first online debate Friday ahead of the July 21 Upper House election, with opposition chiefs voicing concern that ruling bloc-proposed employment deregulation may further worsen the working conditions of younger generations.

Opposition leaders also raised concerns over Japan's planned participation from next month in the Trans-Pacific Partnership free trade talks, saying such an accord could introduce cheaper labor and foreign-oriented employment rules that may result in the domestic labor situation deteriorating even further.

Prime Minister Shinzo Abe, head of the ruling Liberal Democratic Party, defended the nation's pending participation in the TPP negotiations, saying joining them won't affect either the domestic labor market or government regulations on employment.