Bulgaria's ex-head of Parliament Tsetska Tsacheva believes backroom games led to the resignation of the MP Krasimir Stefanov from the center-right opposition party GERB.

Tsacheva, who is also a vice-chair of GERB, stated that none of her party colleagues had information about Stefanov's plans to leave. In her opinion, his decision should be explained with "the way this country is being governed today".

Earlier on Monday, Stefanov, who was also head of Bulgaria's National Revenue Agency in 2011, announced he is leaving his party's parliamentary group.

He did not extensively comment on the reasons for his move, but was quoted by PIK news agency as saying that he was strongly against taking decisions against his own will and being "just a costly button-presser at the parliamentary bench".

Krasimir Stefanov is the third MP to leave the ranks of GERB without quitting the Parliament. The news came shortly after another key official of GERB, Vladislav Goranov, surprisingly resigned as MP on Friday.