The government and ruling parties are considering moving up the start of next year's first Diet session by a few weeks to early January to ease criticism if they decide to skip the usual extraordinary session this fall, sources close to the matter said Saturday.

The ordinary session is normally held for six months from late January. The government and ruling coalition led by Prime Minister Shinzo Abe's Liberal Democratic Party now plan to start it on Jan. 4, the sources said.

The opposition parties have urged the ruling bloc to hold an extraordinary session this fall to discuss urgent issues including the Trans-Pacific Partnership free trade agreement, which was reached by Japan and 11 other nations earlier this month and is expected to expose farmers to more international competition.

But the ruling group has shown reluctance to hold a session this fall, citing tight schedules for Abe's foreign trips.

In the ordinary session, the ruling bloc is expected to seek passage of an extra budget for fiscal 2015 in an attempt to boost the economy because the recovery has been faltering.