TOKYO • A Japanese minister who was the country's top negotiator for a huge trans-Pacific trade deal was accused of corruption yesterday, piling pressure on Prime Minister Shinzo Abe ahead of parliamentary elections this year.

Weekly magazine Shukan Bunshun claimed yesterday that Economy and Fiscal Policy Minister Akira Amari, who also serves as Japan's chief negotiator for the Trans-Pacific Partnership (TPP), and his staff accepted a 12 million yen (S$147,000) "bribe" from a construction firm.

The allegations against a key ally of the Prime Minister come ahead of Upper House elections in July and as the government looks to ratify the TPP, of which Japan has been a key player.

The minister acknowledged that he had met officials from the construction company, which Shukan Bunshun did not identify, but said he could not recall the details.

The magazine said the company was looking for Mr Amari's help in settling problems with a quasi-public housing agency over damage caused by a road project.

It cited a company official as saying the firm had wined and dined the minister's staff and presented them with gifts and envelopes stuffed with cash, including on two occasions handing a total of 1 million yen to Mr Amari himself.

Mr Abe's Liberal Democratic Party government has seen several ministers resign over a variety of scandals.

The latest claims are a potential blow to the premier as he seeks the cooperation of other parties to secure a two-thirds majority in the Upper House needed to help amend Japan's Constitution.

Mr Abe could have another headache if a candidate backed by his ruling party loses a mayoral election in the Okinawan city hosting a US airbase whose planned move elsewhere on the island has set Tokyo and Okinawa at odds.

To help the incumbent's chances at Sunday's polls, Mr Abe's government has dangled prospects of a bigger budget for Okinawa, backing for a Disney resort and aid for impoverished children in Japan's second-poorest prefecture.

Defeat would galvanise resistance to moving the Futenma base to the less populated Henoko area.

The opposition candidate in Ginowan, like Okinawa's governor and many island voters, wants the base off Okinawa altogether.

"The central government always just talks about security and the US-Japan alliance, giving the sense they aren't thinking seriously about Okinawa's benefit," said law professor Tomoaki Iwai, of Nihon University in Tokyo.

AGENCE FRANCE-PRESSE, REUTERS