Japan's main opposition party has apologised after a senior member called the Japanese Communist Party a "termite" in response to the smaller party's call for a coalition against Prime Minister Shinzo Abe's government.
The comment, from Seiji Maehara of the Democratic Party of Japan, came during a television political talk show, when he was asked about the possibility of cooperating with the Japanese Communist Party in an upper house election due next year.
"I know the Communist Party's nature very well," Maehara, a former Democratic Party president and foreign minister, said on the show last week.
"It's like a termite and if you cooperate with them your foundation will collapse."
Maehara's party, which formed a government for about three years until being ousted in elections in December 2012 by the Liberal Democratic Party, apologised to the communists for the "disrespectful expression," Democratic Party secretary general Yukio Edano told reporters late Wednesday.
A communist party spokesman declined to comment on the issue when contacted by AFP.
Public support for Abe's Liberal-led government remains at about 40 percent or higher, despite controversy over landmark security legislation passed by parliament this year that allows Japan to expand military activity abroad.
Some experts have said that voters' disillusionment with the Democratic Party over its perceived poor handling of Japan's security alliance with the United States and the 2011 earthquake, tsunami and nuclear disasters partly explains their reluctant support for Abe.
The communists, who more than doubled their seats in last year's lower house election, have recently called for other opposition parties to form a united front against Abe over the security legislation.
The opposition bloc shares concerns that it violates Japan's war-renouncing constitution, though attitudes toward the security alliance with the United States differ widely.
The Communists and some liberal members of other parties claim it could drag Japan into an American-led war even if Japan is not directly under threat, while more centrist and conservative opposition lawmakers, including Maehara, have openly discussed expanding Japan's role in the alliance.
"One of the reasons why the opposition bloc is hovering near the bottom is that we are being shaken by the Communists' call for (an opposition-led) government," Maehara said last week.
Edano told reporters the Democratic Party "has been and will keep cooperating" with the communists in parliamentary affairs, without mentioning potentially working together in the upper house election.