Bulgarian Parliament Speaker Tsetska Tsacheva has announced discussions are to begin on constitutional changes that would amend the concept of immunity of lawmakers.

At a press conference held by her GERB party (the main ruling party headed by Prime Minister Boyko Borisov) on Monday, Tsacheva said Article 70 of the Constitution could be dropped following an incident on Sunday evening when a nationalist party leader, Volen Siderov, was involved in a late-night fracas in downtown Sofia.

In theory, such a move might result in stripping MPs of immunity to any kind of prosecution except for one related to opinions or statements voiced from Parliament's rostrum.

Under Bulgaria's Constitution (as of October 26, 2015): 

Article 70. (1) (Previous Article 70, amended, SG No. 27/2006) A National Representative may not be detained, and criminal prosecution may not be undertaken there against, save for criminal offences at public law, and then solely on authorization from the National Assembly or, should the latter be in recess, from the Chairperson of the National Assembly. No authorization for detention shall be required where a National Representative is detained in the act of committing a grave criminal offence, but in such a case the National Assembly or, should the latter be in recess, the Chairperson of the National Assembly, shall be notified forthwith.

(2) (New, SG No. 27/2006) Authorization for undertaking of criminal prosecution shall not be required if the National Representative concerned grants consent in writing

Tsacheva's proposal includes expanding the scope of offenses for which a lawmaker is liable to prosecution.

Hours after the Bulgarian Chief Prosecutor demanded that Parliament revoke Siderov's immunity to allow for a third case of criminal proceedings to be launched (immunity can only be lifted in relation to a particular instance of proceedings, and not in general), the Parliament Speaker said current legal arrangements did not match social expectations.