Mr Cook, answering questions to his department, told the Commons ministers had scrupulously followed the due process of law in the case.

Mr Cook said the "due process of law must be carried out and not warped to fit anyone's political agenda".

Pinochet: Under arrest

He added: "One of the very important founding stones of democracy is the rule of law and the clear principle that politicians should not decide who is arrested and who is not arrested.

"It is that principal we are upholding in Britain."

But Shadow Foreign Secretary Michael Howard claimed the handling of the case had been "bedevilled by chaos and confusion".

Mr Howard said: "Why has the government still not established whether or not the Spanish Government as opposed to one Spanish judge has applied for his extradition?"

Mr Cook said it was a matter for the Spanish legal authorities to decide whether to proceed with extradition, just as it was a matter for the British courts how to proceed on it.

Mr Howard's charge came as it became clear that General Pinochet will learn on Wednesday whether he is to avoid extradition from Britain to Spain to face allegations of murder, torture and kidnapping.

The High Court has reserved its ruling on his freedom bid as it emerged that a group of General Pinochet's alleged victims had lodged a formal plea for him to be prosecuted in Britain for torture offences.

Later, the row about General Pinochet's fate broke out again as the visit by President Carlos Menem of Argentina.

MPs welcomed President Menem but the debate spilled over into the subject of the former Chilean dictator who was described by Labour MP for Walsall North David Winnick as a "mass murder" who must not be given amnesty or safe havens.

Boothroyd: Matter is subjudice

At the close of questions, Shadow Home Secretary Sir Norman Fowler raised a point of order calling for a full statement on the situation surrounding General Pinochet.

Labour MP Ann Clywd expressed her frustration about having an early day motion backed by 75 MPs on the subject suspended from the order paper.

Speaker Betty Boothroyd told MPs that due to the current legal proceedings on the legality of General Pinochet's arrest the matter was now subjudice.

The rules on subjudice required there should be no comment awaiting jurisdiction in the courts, she told the Commons.