Constitutional reform is no longer a taboo issue and the Liberal Democratic Party should work together with the Democratic Party of Japan to submit bills to this end to the Diet, Prime Minister Junichiro Koizumi said Wednesday.

"I didn't think the DPJ would be so actively supportive of revising the Constitution," Koizumi said during a group interview with members of the press club at the Cabinet Office.

"If we can, I want to realize the constitutional revision through cooperation between the two parties."