A Pakistani judge issued an arrest warrant Thursday for the ruling party's candidate for prime minister over allegations he illegally imported drugs, injecting fresh uncertainty into efforts to replace the previous premier who was ousted by the Supreme Court.

The warrant was announced after the Pakistan People's Party nominated Makhdoom Shahabuddin, raising suspicion it was politically motivated and aimed at blocking the president's choice to replace Yousuf Raza Gilani. The anti-narcotic force is run by the army, another power center in Pakistan's chaotic polity and one that has at times allied with the judiciary to target elected governments.

Gilani was dismissed Tuesday because he refused to initiate a corruption case against President Asif Ali Zardari, the head of the PPP.

The order, which left the country without a Cabinet, was an escalation of a bruising power struggle between the government and activist judges, who critics say are unfairly prioritizing cases against the government.