Japanese prime minister Yoshihiko Noda has pledged to join talks on a domestically controversial pan-Pacific free trade agreement, signalling his intention to make trade a battleground of the general election.

Mr Noda said Japan’s entry into the Trans-Pacific Partnership, an issue that has generated fierce opposition from agricultural interests and even colleagues within his party, would be a feature of the manifesto for his Democratic party.

“We will simultaneously pursue the TPP and a trilateral free-trade agreement among Japan, China and South Korea. This stance will be outlined in our election manifesto,” Mr Noda said in the southern city of Fukuoka on Saturday, referring to a separate three-way initiative between east Asia’s three biggest economies. Japan must hold elections by next summer.