The Scottish Government will not meet a 90-day deadline on an appeal to allow the Lockerbie bomber to return to his homeland.

However, Justice Secretary Kenny MacAskill insisted that "political and economic" factors will not play any part in his decision on Abdelbaset Ali Mohmed Al Megrahi, who has terminal prostate cancer.

Mr MacAskill is currently considering an application from Libya to transfer Megrahi back home, as well as an application for compassionate release by Megrahi.

The cabinet secretary told a radio interview: "There's a 90-day timescale within the PTA (prisoner transfer agreement) and that's due to end shortly.

"I won't be able to meet it precisely because of information still to come in and I will have to reflect upon what happens.

"But I will thereafter be seeking to act as expeditiously as possible and I think I will seek if I can to deal with questions of prisoner transfer and compassion together."

Mr MacAskill has spoken with the US Attorney General, the US families and British families of victims.

He will also meet with Megrahi next week and said that his final decision will be taken on a variety of factors.

But the cabinet secretary added: "I can be quite clear that this will not be done on any political or economic basis.

"It will be done on the basis of what is just, fair and equitable.

"That's why I've been listening to the representations from the Libyans from the Americans, from the representatives of those who lost loved ones in Lockerbie and thereafter I will take the decision on what I believe is just."

Megrahi is currently appealing against his conviction and Mr MacAskill cannot grant a transfer while this is outstanding in the courts.

But the Justice Secretary is able to consider the application from Libya and could refuse the transfer while the appeal is running.

It emerged earlier this month that no decision on the appeal against the conviction will be reached until the autumn, after one of the judges involved underwent heart surgery.