A new opposition party to be launched March 27 through a merger between the Democratic Party of Japan and Ishin-no-To (Japan Innovation Party) will uphold constitutionalism and envisage a "future-oriented constitution" that matches with time, lawmakers of the two parties said Tuesday.

Citing a draft platform for the new party, the lawmakers said the party will also advocate fighting vested interests, pushing forward political reform, ensuring sustainable economic growth and contributing to world peace and prosperity.

Reference to the Constitution suggests the new party will be in favor of amending the supreme law.