And Prisons Commissioner Mr. Edward Dyer is expecting a protest petition today.

Prisoners have been told to stub out their habit later this year.

Yesterday Mr. Dyer said he fully supported the move.

It would bring Casemates into line with other Government buildings following an anti-smoking drive launched 18 months ago.

Smoking will also be banned at the new prison, which is nearing completion.

It is likely to be a drag for prisoners who find puffing eases the pressures of life behind bars, and gives them something to do.

Mr. Dyer said he believed the ban would start in September.

"I know the prisoners want to talk about it, and a petition has been circulated. It has not arrived on my desk yet, although I am expecting it on Tuesday. I would prefer to read it before making too much comment.'' He added some of the prisoners may be unclear whether a full or partial ban was planned.

Mr. Dyer, who had no idea how many had signed the petition, said smoking was contrary to prison rules. But the rules had been regularly flouted, and never enforced.

"Obviously we can't just suddenly ban it, there will be some assistance for the prisoners to cease smoking.''