The decision of Yildirim, also a member of parliament, comes on the heel of the resignation of another six lawmakers.
In a press conference in the parliament Tuesday, Yildirim accused the AKP of covering corruption, contending that the government is intervening in the graft investigation.
Yildirim recently criticised the removal of the top prosecutor, Muammer Akkas, in the recent corruption and bribery case.
Akkas had protested against the pressure exerted by the government on the judiciary.
On Dec 17, Turkey was rocked by the country's largest ever bribery investigation, in which sons of four cabinet members were detained and a huge amount of money was seized by authorities in their houses.
Soon afterwards, environment minister Erdogan Bayraktar, interior minister Muammer Guler and economy minister Zafer Caglayan announced their resignation. Erdogan then launched a major cabinet reshuffle.
The investigation exposed a bitter feud between Erdogan's government and an influential US-based Muslim cleric, Fetullah Gulen, who wields clout in police and judiciary, according to media.
--IANS (Posted on 01-01-2014)