The three ruling parties said Friday they will withdraw from an agreement with the Social Democratic Party aimed at resolving a 16-year dispute between former workers of the defunct Japanese National Railways and Japan Railway group firms, coalition officials said.

The Liberal Democratic Party, New Komeito and the New Conservative Party will convey their decision to the SDP, which is liaising between the government and the 20,000-member National Railway Workers Union (Kokuro), at a meeting of the four parties early next week.

The agreement seeks a political settlement to the bickering over the firing of thousands of workers in the 1987 privatization of JNR and its subsequent breakup into JR firms.