"I assure this house that if he lands in Pakistan, he will be arrested because he is a PO (proclaimed offender)," Rehman Malik told the upper house of parliament.

"There are three registered cases against him. He has been named in these cases, so ultimately he will be arrested."

In a telephone address to a political rally in Karachi on January 8, Musharraf promised to fly home between January 27-30 to contest general elections now widely expected later this year.

"I'll land in Karachi despite all sorts of dangers to my life," he said.

"I can sacrifice my life if need be for the people of Pakistan."

In February 2011, court issued a warrant for his arrest over the 2007 assassination of ex-prime minister Benazir Bhutto, saying he failed to provide adequate security to protect her.

In 2009, a criminal case was registered against him over his 2007 state of emergency and detention of judges as he attempted to cling onto power.

A spokesman for Musharraf's All Pakistan Muslim League (APML) on Wednesday left the door open to the retired general changing his mind on returning.

"We are not afraid of arrests," party official Mohammad Ali Saif told AFP.

"We are in consultation with party leaders in this regard and Pervez Musharraf will take the final decision."

The authorities in Karachi stood by the threat of arrest.

"We'll go by the order of the court," provincial home minister Manzoor Wassan told AFP in Karachi.

"We have made arrangements for him in prison," he added.

A security official said forces had been ordered to tighten security from January 27-30 in Karachi "to avoid any untoward incident".