Emerging differences between the Liberal Democratic Party and the Japan Innovation Party over how to implement an agreement that reduces parliamentary seats could strain the ruling minority coalition’s unity and test its ability to compromise.

An Oct. 20 agreement between the two parties included a promise, at the insistence of the JIP, to introduce legislation in the current parliamentary session that cuts the number of Lower House seats by 10%, and to aim for its passage.

There are currently 465 Lower House members, and a 10% reduction would mean about 50 fewer seats. The agreement doesn’t specify whether the cuts should be made in the 289 single-seat district seats or the remaining 176 proportional seats.