Farmers vow to resist 'life-threatening' free trade pact

The decision raised protests from farmers, who have until now been a traditional bastion of support for Mr Abe's Liberal Democratic Party.

The Central Union of Agricultural Co-operatives Zenchu vowed to "staunchly resist" the US-led Trans-Pacific Partnership (TPP) "to protect our food, our livelihoods and our survival.

"Along with farmers across the nation, I protest with outrage," Zenchu head Akira Banzai said.

And in Washington, Democrats presented a letter addressed to US President Barack Obama raising concerns that the pact could threaten the US auto industry.

They argued that imports from Japan could increase if the US eliminates its current 2.5 per cent car tariffs and 25 per cent lorry and van tariffs.

Mr Abe claimed that Japan has no choice but to opt for free trade or lose out to other countries that are capitalising on such market opening.

"Japan has run into a big wall - low birthrate, ageing, and lingering deflation - and we have turned inward- looking," he claimed.

"Joining TPP would be the beginning of a new Japan."

He pledged to guard Japan's national interest and ensure that the trade pact would benefit farmers.

However, import tariffs on farm products would almost certainly have to come down.

The average tariff on imported rice is nearly 800 per cent, while rates for butter and sugar are over 300 per cent.

Feelings linger that Japan has been bulldozed into entry by the US.

"We have no choice," said economist Masayuki Kichikawa. "This is a very delicate matter for Mr Abe."

That angers groups which view the plan as a US scheme to usurp Japan's sovereignty.

"Obama has threatened Japan and forced us into joining TPP," financial consultant Takaaki Tabuchi told protesters who gathered near Tokyo's Shibuya train station late on Thursday.

"Preserve our livelihoods. Reject TPP," they chanted.