Pakistan's Supreme Court will announce on Thursday its verdict in a contempt of court case against Prime Minister Yousuf Raza Gilani for failing to act on its directives to reopen graft cases against President Asif Ali Zardari.

A seven-judge bench headed by Justice Nasir-ul-Mulk today reserved its judgement in the case after the completion of arguments by the defence and the prosecution. Gilani could face a six-month prison term and disqualification if he is convicted.

Justice Nasir-ul-Mulk asked Gilani's counsel, Aitzaz Ahsan, to ensure that the premier is present in court when the verdict is announced on Thursday.

"The court will announce its judgement in the case on Thursday," Ahsan told reporters outside the court.

Asked if the premier would appear in court, Ahsan said: "I will inform him about it today and he will Inshallah come to the court."

Ahsan contended that the maximum punishment that Gilani could face, if convicted, was six months in prison.

The Supreme Court has been pressuring the government to revive cases of alleged money laundering against Zardari in Switzerland since December 2009, when it struck down a graft amnesty issued by former military ruler Pervez Musharraf.

Gilani has refused to act, saying the President enjoys immunity within Pakistan and abroad. Gilani had appeared in the apex court twice before and had decided to fight the case.

Even after he was formally charged with contempt of court on February 13, Gilani insisted that he would rather be jailed than approach the Swiss authorities to reopen the cases against the president.

The premier has said throughout the proceedings in the apex court that he had done nothing against the government's rules of business.

During Tuesday's proceedings, Attorney General Irfan Qadir, who is acting as prosecutor in the case, said there was no law on contempt of court in Pakistan.

A contempt of court ordinance was promulgated in July 2003 but it lapsed in December the same year, he added.

Qadir further said there was no evidence against Gilani and that writing to the Swiss authorities would not automatically have led to the reopening of cases against Zardari.

He said the apex court had not directly ordered the premier to approach the authorities in Switzerland. It is the prosecution's duty to ensure that an innocent person is not penalised, Qadir said.

Besides, a section of the media was misreporting details of the case and creating misunderstandings between the government and the judiciary, he added.

Gilani's lawyer Aitzaz Ahsan reiterated his technical objections about the bench hearing the case and maintained that the court should not insist on approaching the Swiss authorities as this would undermine the federation.

The president symbolises the federation and is the supreme commander of the armed forces, he said.

"This is why while Asif Zardari is the President, the court should not insist on writing the letter and absolve the Prime Minister of the charge levelled against him," Ahsan said.

In the past, Ahsan has said that steps could be taken to revive the cases against Zardari after he completed his term as president.

Speaking to the media after the hearing, Ahsan said the accused in such cases are given the benefit of the doubt and that he expected the premier would be acquitted.

Mohammad Farogh Naseem, a leading constitutional lawyer, said Ahsan had not provided any grounds that would allow the apex court to give the premier the benefit of the doubt.