The families of British soldiers killed in Iraq have made a legal breakthrough in their bid for a full public inquiry into why the UK entered the conflict.
The families of the servicemen want a public inquiry into the war
The Court of Appeal ruled they were entitled to apply for a judicial review of the government's refusal to hold an independent inquiry.
The applicants are relatives of four servicemen who died in military action between 2003 and 2005.
Their bid for a judicial review was blocked in the High Court in December.
'Worthy of investigation'
The move was blocked by Mr Justice Collins in the High Court on the basis that their case was "unarguable".
But that decision has now been overturned by appeal judges.
Lawyers representing the prime minister, the attorney general and secretary of state for defence had argued it would be an "unwarranted shift of power" for the courts to make pronouncements on the right of the government to go to war.
The decision to overturn the previous decision was made by a panel of top judges - Master of the Rolls Sir Anthony Clarke, the President of the Queen's Bench division of the High Court Lord Justice Judge, and Lord Justice Dyson.
In their ruling, the appeal judges said: "It is at least arguable that the question whether the invasion was lawful - or reasonably thought to have been lawful - as a matter of international law is worthy of investigation."
But they warned that permission to appeal had been given because the case raised issues "of some general importance" - not because they believed the challenge "has a real prospect of success".
After the move was announced, the families' solicitor, Phil Shiner, hailed it as "a stunning victory".
He said: "The government now have to produce evidence to a full hearing in the Court of Appeal.
"That evidence needs to establish once and for all whether the decision to invade was lawful.
'No legal merit'
"In particular, the government must finally explain how the 13-page equivocal advice from the Attorney General of March 7 2003 was changed within 10 days to a one-page completely unequivocal advice that an invasion would be legal."
The attorney general's office said: "At the full hearing, the government will continue to argue strongly that there is no legal merit in the applicants' case and that issues relating to the use of armed force are fundamentally matters for the elected government to decide, not for determination by the courts."
BBC home affairs correspondent Margaret Gilmore said the decision was a "small victory" and it was unlikely that the hearing would result in the families being given the full public inquiry that they seek.
The hearing will take place at the same court before the same judges on 6 November.