“The people gave us power, and today we are returning it,” Mr. Borisov said on Wednesday morning in Parliament, according to local news reports.
The speaker of Parliament, Tsetska Tsacheva, said the resignation of the prime minister and his cabinet would not be effective until Parliament put it to a vote on Thursday. Since Mr. Borisov controls Parliament, acceptance would seem sure.
The protests — the biggest in at least 15 years — were triggered by electricity price increases and corruption scandals, including one over the nominee to head the state electricity regulatory commission, which sets rates. She was accused of selling cigarettes illegally online and her nomination was later withdrawn.
Tempers were inflamed further when Bulgaria’s finance minister Simeon Djankov, the architect of painful fiscal probity, stepped down on Monday. Rather than allaying anger, analysts said the resignation was greeted by the public as an admission that the government’s economic policies, had not worked.
Tens of thousands of Bulgarians took to the streets across the country to protest. Some yelled “Mafia!” Others burned their utility bills.
While the country’s fiscal prudence has helped it to avoid having to seek an international bailout like Hungary or Romania, analysts said that rising unemployment and weak growth, coupled with wage and pension freezes and tax increases, had mobilized the country’s increasingly disgruntled middle class, who felt themselves squeezed during the financial crisis.
Opposition political parties had been trying to exploit public anger over the government’s austerity measures as general elections planned for July approached. Elections are now expected in April or May, and analysts said the opposition Socialist party was expected to benefit from the turmoil.
Daniel Smilov, program director at the Center for Liberal Strategies, a political research organization, in the Bulgarian capital, Sofia, said that Bulgarians were disillusioned that the overthrow of Communism in 1989 and the country’s subsequent democratization had not delivered the expected prosperity.
Bulgaria has struggled to shed a reputation for lawlessness and corruption. It remains poor, with an average monthly wage of just $480, the lowest in the European Union.
“What we are seeing is the result of a general distrust in government and the political system,” Mr. Smilov said, noting than protests had engulfed wealthy as well as poorer regions of the country. “These are not the bottom layers of society, but people in the middle strata who been hit hardest by the financial crisis. They fear they are losing their status, and they might become poor very fast.”
Trying to appease the protesters, the prime minister said on Tuesday that the license of the Czech utility CEZ, which provides power to many residential customers in Bulgaria, would be withdrawn. Mr. Borisov cited beatings of protesters Tuesday by the police as one reason.
“Every drop of blood for us is a stain,” he said. “I can’t look at a Parliament surrounded by barricades, that’s not our goal, neither our approach, if we have to protect ourselves from the people.”
Mr. Smilov said that after the Parliament accepted the government’s resignation, President Rosen Plevneliev would then appoint a caretaker government. Mr. Borisov said his party would not participate in an interim government.
Mr. Borisov’s resignation could signal the political demise of one of the country’s most colorful political figures. A former karate instructor, bodyguard, fireman and mayor of Sofia with a shaved head and a talk-tough approach, Mr. Borisov was once viewed as being so invincible that Bulgarians called him “Batman.”
As the owner of a private security company, he provided security services for Todor Zhivkov, the former Communist leader of Bulgaria. Mr. Borisov was then the personal bodyguard for Simeon Saxe-Coburg-Gotha, the child czar who returned to be elected prime minister in 2001.
Mr. Borisov rose to oversee the police at the Interior Ministry, before being elected mayor of Sofia and then becoming prime minister in 2009.
“Mr. Borisov is a typical populist leader who came to power promising to take revenge against the transition on behalf of the poor,” says Andrei Raichev, a political analyst at Gallup International in Sofia. “Now the people realize that they were lied to.”
Mr. Raichev said that no one could predict how the public will react to the resignation. “We could even reach the absurd situation that the protests continue against no one,” he said. “Which means that they are against everyone.”
This article has been revised to reflect the following correction:
Correction: February 20, 2013
An earlier version of this article and an accompanying photo caption misspelled the given name of Bulgaria’s prime minister. He is Boiko Borisov, not Boyko.
