Former foreign secretary Jack Straw faces legal action brought by a Libyan dissident and his wife who allege the UK participated in their abduction and rendition to Tripoli more than a decade ago.

The action follows a victory for the couple at the UK's highest court.

He is named as one of the defendants in an action brought by Abdel Hakim Belhaj and his wife Fatima Boudchar, who say they were tortured after their kidnap during the days of Colonel Gaddafi's regime.

Mr Straw, who denies complicity in any "unlawful rendition or detention", issued a statement on Tuesday after the Supreme Court rejected a Government bid to block the couple's claim, which can now go to trial.

He said: "This judgment is about some important points of law, related to how far it is possible to bring into a court process in the UK actions of sovereign states abroad."

He pointed out that "at no stage so far have the merits" of the case "been tested before any court".

Mr Straw added: "That can only happen when the trial of the action itself takes place.

"I repeat what I said in the House of Commons in December 2013, that as foreign secretary I acted at all times in a manner which was fully consistent with my legal duties, and with national and international law.

"I was never in any way complicit in the unlawful rendition or detention of anyone by other states. "

In their claim, Mr Belhaj and his wife also name Sir Mark Allen, MI6's counter-terrorism chief at the time they were snatched in 2004.

The action is also against the Home Office and Foreign Office.

Liability is denied.

The couple have offered to settle for a token £1 from each defendant and an apology and an admission of liability for what they suffered.

International human rights group Reprieve and the Belhaj family say the abduction involved a joint MI6-CIA operation following the 2004 "deal in the desert" in which the government of Tony Blair re-opened diplomatic links with Gaddafi.

According to Reprieve, part of the deal involved the illegal kidnapping and flying of Libyan dissidents to Tripoli.

Government lawyers had argued through the courts that the Belhaj claims should be barred under state immunity and the foreign "act of state" doctrine, which prohibits the courts of one country sitting in judgment on the acts of the government of another one within its own territory.

The High Court agreed with the Government's stance and ruled that the claims should be struck out.

However, the Court of Appeal reversed the High Court ruling in October 2014.

It said the act of state doctrine might not apply to alleged breaches of international law or human rights obligations, even in cases where the court would be required to conduct an investigation into the validity of the conduct of a foreign state.

The appeal judges said there was a "compelling public interest" in allegations of unlawful rendition and "particularly grave violations of international law and human rights" being investigated by the English courts.

Now seven Supreme Court justices have upheld that decision.

Lord Mance, announcing the Supreme Court's findings, said that "state immunity is no bar to the claims", and the defendants had not "on the assumed facts shown any entitlement to rely on the doctrine of foreign act of state".

He said: "The appeals are dismissed and the cases may proceed to trial."

Sapna Malik, of law firm Leigh Day which is representing Mr Belhaj, said: "The Supreme Court today has delivered an emphatic judgment upholding the rule of law, particularly in the face of breaches of rights recognised as fundamental by English statute and common law, in which British defendants are alleged to have been complicit."

UK Government lawyers had argued that the compensation claim could not be heard in a British court because it would damage relations with the US.

The argument was dismissed by the seven justices - court president Lord Neuberger, sitting with Lady Hale and Lords Mance, Clarke, Wilson, Sumption and Hughes.

Reprieve said the Government has already settled a related claim out of court by paying compensation to another family who were rendered to Libya in the same "deal in the desert" conspiracy weeks after Mr Belhaj and Mrs Boudchar.

The human rights group said cases came to light after the fall of Tripoli and Gaddafi's regime in 2011, when faxes from MI6's then counter-terrorism director Sir Mark Allen describing the rendition flights were found in Libya's intelligence headquarters.

Lord Mance described in the lead Supreme Court ruling how Mr Belhaj, a Libyan national and opponent of Gaddafi, and his then-pregnant Moroccan wife had attempted - probably under other names - to take a commercial flight from Beijing to London.

Instead, "for whatever reason", they were deported by the Chinese authorities to Kuala Lumpur where they were detained.

The judge said: "MI6 is alleged to have become aware of their detention and on March 1 2004 to have sent the Libyan intelligence services a facsimile reporting their whereabouts.

"This is said to have led to a plan being developed to render them against their will to Libya.

"Thereafter, they allege, they were unlawfully detained first by Malaysian officials in Kuala Lumpur and then by Thai officials and United States agents in Bangkok, before being put on board a US airplane which took them to Libya.

"There they were further detained, in the case of Mrs Boudchar until 21 June 2004, in the case of Mr Belhaj until 23 March 2010."

The judge said: "They allege that they suffered mistreatment amounting to torture at the hands of US agents in Bangkok and in the airplane and at the hands of Libyan officials in Libya."

The couple are accusing the UK of being involved in "arranging, assisting and encouraging their unlawful rendition".

The judge said they were relying on a letter dated March 18 2004, claimed to have been written by Sir Mark, "allegedly a senior official of the Secret Intelligence Service ("SIS"), to Mr Moussa Koussa, head of the Libyan External Security Organisation".

"The letter congratulated Mr Moussa Koussa 'on the safe arrival of (Mr Belhaj)'," said the judge.

"It said that 'This was the least we could do for you and for Libya to demonstrate the remarkable relationship we have built over recent years'.

"It indicated that British intelligence had led to Mr Belhaj's transfer to Libya, although the British services 'did not pay for the air cargo'.

The judge said: "Mr Belhaj and Mrs Boudchar further allege that the United Kingdom 'conspired in, assisted and acquiesced in torture, inhumane and degrading treatment, batteries and assaults inflicted upon (them) by the US and Libyan authorities."

The judge stressed the allegations were based on an alleged awareness "of the risks of torture of detainees in United States or Libyan hands".

It was also pleaded that "the renditions took place as part of a co-ordinated strategy designed to secure diplomatic and intelligence advantages from Colonel Gaddafi".

The judge said Mr Straw and Sir Mark Allen had said the Official Secrets Act made it impossible for them "to advance any positive case in response to the allegations against them".

The Foreign Office and Home Office said: "It is the position of Her Majesty's Government that it would be damaging to the public interest for them to plead to such allegations."

Lord Mance said the seriousness of the Belhaj allegations of "apparently arbitrary rendition accompanied by severe mistreatment" ruled out the judiciary being required by the "act of state" doctrine to abstain from hearing their case.

English law had set limits to the doctrine, said the judge, and English law recognised the existence of fundamental rights going back to the Magna Carta, which stated that: "no free-man shall be taken, or imprisoned, or dispossessed" of his liberties "excepting by the legal judgment of his peers, or by the laws of the land".

Further, torture "has long been regarded as abhorrent by English law".

The judge said: "Sovereign states who without justification and without permitting access to justice detain or mistreat individuals in the course or in relation to their conduct of foreign relations or affairs have sovereign immunity in foreign domestic courts.

"But I see no reason why English law should refrain from scrutinising their conduct in the course of adjudicating upon claims against other parties involved who enjoy no such immunity there, where the alleged conduct involves almost indefinite detention, combined with deprivation of any form of access to justice and, for good measure, torture or persistent ill-treatment of an individual."

Reprieve lawyer Cori Crider said the ruling was particularly significant given US president-elect Donald Trump's comments on the campaign trail about bringing back waterboarding "and a hell of a lot worse".

She said: "In 72 hours, a would-be torturer will take the reins of Earth's most powerful security state. So this case isn't 'just' about history - the stakes couldn't be higher.

"We enter the Trump era with not a soul held to account for Britain's past role in rendition. No official has condemned Trump's torture boasts. Our intelligence agencies may well be pressured to help America torture again."