How much damage have Edward Snowden's revelations caused to British national security?
A witness statement given to the high court claims that the information seized contains information which could directly endanger lives.
The independent reviewer of terrorism legislation said he will examine the detention of David Miranda at Heathrow Airport.
In a statement published on journalist Glenn Greenwald's new website, The Intercept, David Miranda said:
I will appeal this ruling, and keep appealing until the end; not because I care about what the British Government calls me, but because the values of press freedom that are at stake are too important to do anything but fight until the end.
I'm of course not happy that a court has formally said that I was a legitimate terrorism suspect, but the days of the British Empire are long over, and this ruling will have no effect outside of the borders of this country.
I'm convinced they've hurt their own country far more than me with this ruling, as it emphasises what the world already knows - the UK has contempt for basic press freedoms.
David Miranda, a journalist's partner held for nine hours at Heathrow under anti-terror laws, has lost his High Court claim that he was detained unlawfully.
The Home Office has said that the reason behind examining files seized from David Miranda is; "crucial public security concerns."
We are pleased that David Miranda's legal team and the court have agreed with us that there is a compelling case for this highly-sensitive stolen material to be retained by the police, and that all the documents retrieved may be examined on both national security and specified criminal grounds.
– Home Office spokesman
The examination of this documentation is motivated by crucial public security concerns, something clearly demonstrated by today's consent order and the release of the witness statements.
Gwendolen Morgan, of law firm Bindmans, representing Mr Miranda, said outside court that the Home Office and police had made "sweeping and vague assertions about national security".
She said Mr Miranda "does not accept the assertions they have made".
He "looks forward to the opportunity to have the Government's actions and assertions fully scrutinised" at the hearing in October, she added.
Solicitors for David Miranda, the partner of the Guardian journalist, who was detained at Heathrow, have agreed that emergency interim injunction granted last week should continue until there is a full hearing.
This will prevent the Home Secretary and the Metropolitan Police from inspecting, copying or disturbing the date and material seized from Mr Miranda, unless it is necessary to protect national security or to establish whether Mr Miranda was involved in an act preparatory to terrorism.
One additional exception, that it can be used for the collection of information that may be of use in terrorism. This order will remain in place until there is a full judicial review into the legality of the detention of Mr Miranda under the terrorism laws.
An agreement has been reached over the terms of a temporary order relating to the extent of the use of material seized from a Guardian journalist's partner held at Heathrow under anti-terror laws, High Court judges in London heard today.
David Miranda, who was held at Heathrow Airport for nine hours under anti-terror laws, launched an application for judicial review, arguing that his detention was a misuse of Schedule 7 of the Terrorism Act 2000 and breached his human rights.
At a hearing last week, Mr Miranda sought an interim injunction in an action against the Home Secretary and the Met Police to prevent the Government, its agencies and the police from further ''inspecting, copying or sharing'' the data until the High Court can hear his judicial review challenge.
Today's argument before Lord Justice Laws and Mr Justice Kenneth Parker at the High Court will centre on what, if any, injunction should be imposed pending the hearing later in the year.
Legal action for an injunction aimed at stopping examination of material seized from a Guardian journalist's partner returns to the High Court today.
Mr Miranda's partner is Glenn Greenwald, who has worked with US whistleblower Edward Snowden on a series of security services exposes.