Mr Stanishev's Socialists govern with two other parties
Bulgaria's Prime Minister Sergei Stanishev has carried out a major cabinet reshuffle as the EU steps up scrutiny of his administration.
He sacked the ministers of defence, agriculture and health, and named a new interior minister to replace Rumen Petkov who resigned last week.
The EU has urged Bulgaria, a new member state, to take swift action to tackle corruption and organised crime.
A new Bulgarian deputy PM will oversee the management of EU aid money.
Bulgaria is worried that the EU will cut aid if a report due out in July on its efforts to stamp out corruption is critical.
Mikhail Mikov was named as the new interior minister, replacing Mr Petkov, whose resignation took place amid a corruption scandal that tarnished his ministry.
Two senior police officers were accused of passing official secrets to alleged crime bosses. Bulgaria has also been plagued by contract killings.
Bulgaria's ambassador to Germany, Meglena Plugchieva, will become the new deputy prime minister without portfolio to oversee the use of EU funds.
The other new appointments were: Valeri Tsvetanov as agriculture minister, Nikolai Tsonev as defence minister and Evgeni Zhelev as health minister.