Seven of Britain's most senior judges today begin re-hearing Gen Augusto Pinochet's claim that he is immune from prosecution outside Chile on charges of murder, torture and kidnap.
If they find in favour of the former dictator, he will be taken to a military airfield where a Chilean air force plane is on standby to fly him back to Santiago.
But if they rule against him, a flurry of appeals will undoubtedly follow, and the 83-year-old general could find himself an unwilling guest in Britain for many months to come.
The Sunday Telegraph quoted Gen Pinochet as saying he was resigned to dying in Britain during interminable legal arguments over whether he can be extradited to Spain.
Yesterday hundreds of Chilean exiles took part in a rally in London, the largest ever protest against Gen Pinochet since he was arrested last October. Many wore white masks with question marks on the forehead to draw attention to the hundreds of people who disappeared during his rule.
Witnesses said the demonstration, which ended at Trafalgar Square, passed peacefully.
In November five judges of Britain's highest court, the House of Lords, ruled by three to two that Gen Pinochet had no immunity as a former head of state.
Their decision allowed proceedings to extradite him to stand trial in Spain, where a judge has claimed his victims included Spanish citizens, to go ahead.
However, in December, in a move which made British legal history and deeply embarrassed government law officers, that decision was set aside.
Gen Pinochet's lawyers had protested that one member of the panel, Lord Hoffmann, had failed to declare his close connections with the human rights group Amnesty International.
A lawyer representing Amnesty was allowed to intervene in the November hearings to put its argument that international law does not protect a former head of state from standing trial abroad for serious offences committed in his country. Amnesty has leave to be represented at the re-hearing, which will take place before a new seven-judge panel presided over by Lord Browne-Wilkinson, Britain's senior Lord of Appeal.
The public relations battle against Gen Pinochet is to step up its campaign, boosted by the arrival of Mr Baltasar Garzon, the Spanish judge who ordered the arrest of Gen Pinochet last year. He will attend the hearing.
Mr Garzon is expected to fly into Britain amid heavy security to attend today's Law Lords hearing on the fate of the former dictator.
It will be the first time Mr Garzon has appeared in the UK since the Pinochet saga began. - (Reuters, PA)
Gen Pinochet is already defeated, writes the Chilean novelist, Isabel Allende, in a lengthy article in the New York Times yesterday. "By pursuing the general, assembling a strong legal case and issuing the extradition request, Garzon has already achieved the salutary result of Pinochet's moral ruin," writes the niece of the former Chilean president, Salvador Allende.