Prime Minister Shinzo Abe is expected to declare Japan’s participation in the Trans-Pacific Partnership free-trade negotiations at a news conference Friday, and the ruling Liberal Democratic Party plans to back his announcement, sources said Wednesday.

Abe is thought to be hoping to formally present his plan, and gain backing for it, at a general assembly of his ruling LDP on Sunday.

The LDP panel on the TPP continued discussions Wednesday to draw up demands for joining the trade talks, including measures to protect the politically sensitive, and protected, agricultural sector.

In a draft resolution to be adopted later in the day, the party’s committee on the TPP will state “If the prime minister decides to enter the (TPP) negotiations, he should respect the February party resolution.” That resolution called for Japan to clearly show it intends to protect the country’s interests.

In consideration of calls from the agricultural sector to retain tariffs on key produce such as rice and wheat, the upcoming resolution will also note that Japan “should not hesitate to leave the negotiating table” if its national interests are threatened.

It will also refer to concerns that the public insurance system could fall apart under the TPP, while noting the need to promote parliamentarian-level exchanges with countries involved in the TPP talks to gather more information.

Some LDP lawmakers have expressed concern about, and opposition to, Japan taking part because of the potentially adverse impacts on domestic industries and the livelihood of citizens. If the discussions get too heated at the LDP panel, the date of the announcement of participation may be delayed.

Separately, a working group of New Komeito, the LDP’s coalition ally, agreed in a Wednesday morning session that Abe should disclose estimates on the financial impact that the TPP would have on the agricultural sector.

After announcing Japan’s participation, the government will likely take steps to start the negotiations, including soliciting endorsements from the United States, Australia and New Zealand. Eleven countries are involved in the regional trade initiative.

Japan will probably not enter into the negotiations before June because the United States requires at least 90 days to secure congressional approval even if the administration endorses Japan’s participation.

TPP protest rally

The nation’s largest farm lobby and consumer groups linked to the sector staged a protest rally Tuesday in Tokyo ahead of Prime Minister Shinzo Abe’s expected announcement that Japan will join the Trans-Pacific Partnership free-trade negotiations.

About 4,000 people took part in the rally, according to the Central Union of Agricultural Cooperatives (JA-Zenchu), which is part of the Japan Agriculture group.

The farm lobby, which was joined by seven other groups, including consumer cooperatives linked to the highly state-protected farm and fisheries sectors, has long opposed Japan’s joining the U.S.-led trade talks on grounds that the elimination of tariffs would damage the agriculture sector with an influx of cheap imported produce.

“Anxiety and anger are spreading around us because we have not received a sufficient explanation from the government,” Akira Banzai, head of the union, said in his opening address, calling the TPP “a drastic agreement that will change the way the nation deals with food.”