The House of Lords was today urged to bow to the "overwhelming weight of popular democratic opinion" and allow the continuation of the extradition process against General Augusto Pinochet.

Jeremy Corbyn, Labour MP for Islington North, submitted the first 30,000-signature consignment of a Europe-wide petition urging the Law Lords to reject the 83-year-old former dictator's claim to immunity from arrest and extradition to Spain over alleged human rights crimes.

The petition, organised by the Committee against Impunity, a group of Chilean victims of Pinochet's regime, has so far gathered 850,000 names.

Mr Corbyn, vice chairman of the Parliamentary Human Rights Group who also chairs the All Party Group on Chile, submitted the petition to the House of Lords' judicial office.

"The petition is obviously not admissible in the legal sense before the Law Lords," acknowledged Mr Corbyn. "Nevertheless, I hope when reaching their verdict they remember the law is there to serve the people. The overwhelming weight of popular democratic opinion all over the world says this international terrorist must be brought to justice."

Mr Corbyn derided the publicity campaign waged in recent weeks by Pinochet's supporters.

"Signatures for this unprecedented petition were collected in hardly any time with almost no resources. This contrasts with the costly, futile campaign waged by Pinochet's apologists," said Mr Corbyn.

Mr Corbyn's move came as a panel of seven Law Lords started the ninth day of a hearing into whether the general is immune from arrest and potential extradition to Spain over human rights abuses during his 1973-90 rule.

The hearing was made necessary by the Law Lords' move last month to set aside their previous decision to overturn a High Court ruling that Pinochet has immunity.

That move was prompted when Pinochet's lawyers' complained that Lord Hoffmann, one of the Law Lords who voted to quash the High Court's decision, failed to declare in advance his long-standing relationship with Amnesty International.

At the hearing itself Lawrence Collins QC, representing the Chilean government, said the government deplored the human rights violations of former dictator Augusto Pinochet's regime - but only Chilean courts could rule on who was responsible.

He continued to challenge the jurisdiction of the English courts to deal with the case, as Chile sought to assert its sovereignty and the jurisdiction of its own courts.

Collins told the seven-strong panel of Law Lords that the current Chilean government, far from seeking to hide the facts of what went on between 1973 and 1990 when Pinochet ruled Chile, had "endeavoured to get out details of these matters".

He referred the judges to extracts in Chile's written submissions to the court from the report of the National Commission of Truth and Reconciliation.

The Commission was set up by the 1990-1994 government of Patricio Aylwin to investigate human rights violations and search for Chileans who had disappeared.

"Your lordships will see fairly horrific examples which I will not read," Collins said after referring the judges to a passage in the report. "My instructions are to make absolutely clear that the Government of Chile does deplore these events but considers that these are not matters for foreign courts."

In the court's last session on Thursday, Mr Collins argued that it is fundamental that the immunity of a head of state, or a former head of state, from prosecution in a foreign state is an aspect of the immunity of the state itself.

Today Mr Collins said there were numerous authorities in English law to support the proposition that legal actions against a representative of a foreign government were proceedings against the state itself.

If a state's immunity were denied to its agents, then that immunity would be "illusory", Mr Collins argued, adding that the crimes alleged against Pinochet are unproven and the immunity sought is from being tried at all.

"What the state is immune from is not a finding of guilt - it is immune from adjudication. The English courts have no part to play in the adjudication of responsibility," said Mr Collins, reiterating the rationale behind Chile's position - that the sovereign acts of one state are not matters on which the courts of another state will adjudicate.

"The only courts which have jurisdiction, because of immunity, are those of the home state."

State immunity was unaffected by the jurisdictional provisions of international treaties, unless it was explicitly waived, he added.

In particular, Mr Collins said, the Convention Against Torture 1984 and the Convention against the Taking of Hostages 1979, which featured prominently in the prosecution case against Pinochet, left "untouched" the immunity enjoyed by heads, and former heads of state.

The hearing was adjourned until tomorrow.

It is expected to be concluded on Wednesday or Thursday, after which the judges will take a few days to privately debate the matter further, before announcing their final decision on the issue.