Most of these came from Labour members, who are suspicious of Chile's promise to try the general in Santiago if the extradition request is refused.

The issue was not raised at home secretary's questions on Monday, when MPs from all parties get their chance to quiz the department's ministers.

Jack Straw: Faces a hard task, with pitfalls on both sides

Mr Straw has already been granted a week's extension of the normal ruling period in this case in order to consider the complicated and contentious arguments laid before him.

The final date for representations to the home secretary on the case is Monday.

Those demanding General Pinochet's release warn of scuppering trade relations with Chile and point to the former dictator's failing health now he has turned 83.

But the majority of Labour MPs appear to agree with the view of Trade Secretary Peter Mandelson who said it would be "gut-wrenching" to watch the general walk free.

"Where are they?": During Pinochet's reign many people simply disappeared

General Pinochet is accused of crimes of genocide and torture, which he ordered during his time as Chile's ruler.

When he agreed to stand down as president and become a senator for life, he negotiated permanent immunity from prosecution within his country.

The UK's courts initially took the view that his meant he also had immunity from prosecution in any other country and ruled against the request for his extradition.

But the Law Lords over-turned this decision by a majority of 3-2, saying crimes against humanity could not be granted such a get out clause.

Chile's foreign minister Jose Miguel Insulza promises a trial at home

The Labour chairman of the all-party human rights group, Ann Clwyd, told BBC Radio 4's Today programme she welcome this as a precedent.

"We think it's a very important decision and it's going to signal to all those dictators guilty of torture and genocide and crimes against humanity that the UK will not provide them a hiding place and in future they can expect the same kind of treatment."

Donald Anderson, Labour chairman of the Commons Foreign Affairs Select Committee, also urged Mr Straw to let the extradition go ahead.

He told BBC News Online he had no concerns about setting such a legal precedent for the conduct of international relations.

"Let's tyrants tremble," he said, dismissing the suggestion that prosecutions could be brought against a large number of former state leaders.

He added that he had no time for former prime minister Margaret Thatcher's argument that General Pinochet should be freed on compassionate grounds.

"It bears ill for a guy who gave no compassion to his enemies to expect any now," he said.