John Sergeant: "The diplomatic problem for the government is growing"

In a letter to The Times newspaper, the former Tory prime minister, who entertained General Pinochet at her home two weeks ago, said the 82-year-old Chilean senator helped shorten the 1982 Falklands War against Argentina and saved many British lives as a result.

In contrast, present UK Prime Minister Tony Blair, in his first public comments about the arrest, has condemned General Pinochet's actions while in power.

General Pinochet: Facing possible extradition

Lady Thatcher compared the general's treatment to the impending visit next week of the Argentine President Carlos Menem.

"It would be disgraceful to preach reconciliation with one, while maintaining under arrest someone who, during the same conflict, did so much to save so many British lives," she writes.

"General Pinochet must be allowed to return to his own country forthwith."

Tories back intervention

Conservative MP David Wilshire, a member of the Commons foreign affairs select committee, backed Lady Thatcher's intervention as "absolutely right".

John Andrew: "Thatcher insists it is not for Spain, Britain or any other country to interfere"

He told BBC Radio 4's Today programme: "I'm quite delighted that somebody has spoken out and opened up a debate so that we can examine the Blair government's incompetence and double standards in all of this."

He said Mr Blair was happy to "cosy up" to left-wing dictators during his recent visit to China.

Mr Wilshire compared the political situation in Chile to the Northern Ireland peace process.

The people of Chile, he said, "have decided just as this government has decided in Northern Ireland to put the past behind them - to look for compromise and to work for the future.

"We should not step in and mess that up for them. We have caused chaos in Chile."

Archbishop of Canterbury: "I am confident that our government will be compassionate in this situation"

The Archbishop of Canterbury said he hoped General Pinochet would be treated humanely.

Despite being repeatedly pressed on the same programme, Deputy Tory leader Peter Lilley refused to be drawn on whether he agreed with Lady Thatcher that General Pinochet should be released.

He said: "I thought it was right that Mrs Thatcher should raise something from her own experience."

Human rights abuses

Political Correspondent Carole Walker: "Thatcher's comments won't make much difference"

General Pinochet was arrested on Saturday at a private clinic where he was recovering from an operation on his lower back.

He was held after Spanish judges investigating the disappearance and murder of Spaniards during the former dictator's rule between 1973 and 1990 made a preliminary request for his extradition from the UK.

The general is under guard in a London clinic

Lady Thatcher said in her letter that there were abuses of human rights in Chile and acts of violence on both sides of the political divide after the coup which brought the general to power.

However, the people of Chile had decided how to come to terms with their past, she went on.

"An essential part of the process has been the settlement of the status of General Pinochet and it is not for Spain, Britain or any other country to interfere in what is an internal matter for Chile," she said.

Blair condemns Pinochet

Lady Thatcher's intervention came as Mr Blair made his first public comments on the arrest of the former dictator.

Chief Political Correspondent John Sergeant: Lady Thatcher can still cause quite a stir

In a series of interviews in European newspapers, Mr Blair underlined the government's insistence that the arrest was a judicial matter, not a political one.