The radical Islamic group holding Scottish journalist Alan Johnston in captivity in Gaza was delivered an apparent deadline of last night to release him or face having him liberated by force.

Hamas, the militant group which ousted Palestinian security forces from Gaza last week, delivered the ultimatum to the BBC correspondent's kidnappers yesterday.

The reporter, whose parents live in Lochgoilhead, Argyll, was abducted in March by a group calling itself The Army of Islam.

On Friday, Hamas said that Mr Johnston should be freed and that it was in contact with his abductors. A Hamas spokesman told the BBC yesterday that if Mr Johnston was not freed, it would be the role of the Palestinian government to work for his safe release.

Hamas seized control of Gaza last week and was ousted from the Palestinian government.

It defeated Fatah, the secular group aligned with Mahmoud Abbas, the Palestinian President, in parliamentary elections in January 2006, and asserts its authority to form the legal government of the Palestinian territories.

Mahmoud Za- hhar, the former Palestinian foreign minister who is believed to be a leader of Hamas, told the BBC Arabic Service: "Alan Johnston was discussed with the kidnappers. They have been given a deadline of today, Monday, to respond.

"They will be contacted, they may have already been contacted, for his release. If he is not released then the role of the current government is to work for his release, safe and sound."

In a tape released to the news agency Reuters last night, Mr Zahhar said: "First of all, this man I am respecting very well, I am respecting his official and professional activities.

"I met him many times and I worked with him, co-operated with him and am respecting him.

"I am looking to see him free and we are going to continue our efforts to set him free."

He continued: "The last appointment given for the kidnapper is today.

"If they are not going to release him smoothly we are going to use every way in order to set him free and set him safe in order to give chance for every press media man, for everybody whether he is Arabic or foreigner, to work in Gaza and we are hoping and we are praying to succeed in our mission."

Hamas has consistently maintained that foreign journalists should be welcomed to the Palestinian territories and treated as guests. He added: "If he is not released, we would use all means to secure his life and to free him."

The Army of Islam has threatened to kill Mr Johnston if certain Islamist prisoners, in particular Palestinian-born cleric Abu Qatada, who is detained in the UK, are not released.

In a video released on Sunday, Mr Johnston's captors denied they had reached a deal with Hamas for his imminent release, but acknowledged that there had been "developments" in meetings with Hamas.

"There are developments and we will let you know when there are new developments," a masked spokesman said.

"If they do not meet these demands there will be no release of this prisoner, but if things get worse we will get closer to God by killing this journalist."

Mr Johnston was the only Western reporter permanently based in Gaza, and his abduction has provoked appeals for his release from politicians and human rights groups around the world.

Several foreigners have been seized in Gaza in recent years and all have been released unharmed but none has been held as long as Mr Johnston.