Joe Campbell: Britain insists sentences would be served in Scotland

Sir Jeremy Greenstock, speaking to reporters in New York, was responding to Libyan questions about conditions for a proposed trial of the two.

After the bombing of an airliner over Lockerbie in 1988 London and Washington demanded that the two Libyan suspects be handed over for trial in the UK or the US.

But in August this year Britain and the US softened their position and agreed that the two - Abdel Baset Ali Mohamed al-Megrahi and al-Amin Khalifa Fhimah - could be tried in the Netherlands under Scottish law.

Colonel Gaddafi...keen to lift sanctions

Libyan leader Colonel Muammar Gaddafi has agreed in principle with the proposal.

But he has raised numerous questions about how the trial would work and has demanded that the pair, if found guilty, serve their sentences either in the Netherlands or in Libya.

Sir Jeremy said any Libyan witnesses at the trial would be guaranteed immunity from prosecution.

Rob Watson reports from the UN in New York

But he said if convicted of the Lockerbie bombing the two must serve their sentences in Scotland. He said the issue was non-negotiable.

Britain has been giving Libya assurances about the way the two would be treated in Scottish jails.