General Pinochet's arrest in a London clinic last Friday has sparked a diplomatic row between London and Santiago, and prompted warnings by Tory MPs that it could destabilise Chile.
There have been signs of discomfort in the Government over right-wing accusations that the arrest was politically motivated. Downing Street insists the move was a "judicial process - not political", and has refused to endorse the remarks by Peter Mandelson, the Trade and Industry Secretary, that the idea of giving the "brutal" ex-dictator diplomatic immunity was "gut-wrenching".
Michael Howard, the shadow Foreign Secretary, called last night for an urgent Commons statement, saying: "The aura of confusion around these events is now unmistakable."
But the Labour left is delighted by the arrest. MPs led by Ann Clwyd, who chairs the parliamentary human-rights group, are seeking an urgent meeting with the Attorney General to urge him to prosecute General Pinochet under the 1988 Criminal Justice Act for acts of torture.
The Metropolitan Police was also urged by the human-rights group Amnesty International to use the legislation to prosecute the general, warning that he could escape justice if an application to extradite him to Spain fails. A Home Office source confirmed that the 1988 Act could allow for a prosecution for acts of torture abroad, "regardless of the nationality of the offender or the location of the events. The Crown Prosecution Service would have to look at it to see if there is a case. It is a matter for the Attorney General."
There was growing support among Labour backbenchers for a Commons motion tabled by Ms Clwyd welcoming the detention of General Pinochet.
Spanish authorities have 40 days to deliver their extradition order, which is based on allegations of murder of Spaniards in Chile.
General Pinochet, 82, who arrived in Britain on 21 September for back treatment, was said yesterday to be "very, very sick" by Alberto Espina, a representative of a right-wing party in Chile. "What you are doing in the end is a danger for our democratic system," Mr Espina said of the arrest.