Samoa parliament has approved a bill which the government claims will add to political stability following its dispute with the Tautua Samoa Party last year.
The Constitution Amendment Bill was backed by a two thirds majority and states that an MP's seat becomes vacant, if he or she quits their party and joins another party.
It also says a seat is vacant if a member joins a party or organisation with political aims which is not yet registered or different from the party they belonged to when they entered parliament.
Last year, by-elections were called for nine seats after a controversial speaker's ruling but in court the Tautua Samoa Party members won and were re-instated.
