The Order, Law and Justice (OLJ) parliamentary group of Yane Yanev was disbanded on December 3, Bulgarian media reported.
After Member of Parliament Mario Tagarinski had handed in his resignation earlier in the day, the group was left with only nine MPs, while rules of the Parliament require that a parliamentary group has at least 10 members.
Tagarinski would remain an independent MP and does not have the right to join another group. Neither would another MP be allowed to join the parliamentary group of OLJ.
The OLJ is the first parliamentary group in the current National Assembly to disband.
Yanev told Bulgarian television bTV that the group would probably appeal for a change of the rules of Parliament to have the minimum number of members of a parliamentary group reduced to eight.