The High Court will rule today on whether former paratroopers who are facing questioning over Bloody Sunday should be detained and transferred to Northern Ireland for interview by police.
Lord Chief Justice Lord Thomas described the case at a recent hearing as "a matter of great public interest".
The ex-soldiers - referred to as B, N, O, Q, R, U, V - are seeking judicial review against the Chief Constable of the Police Service of Northern Ireland (PSNI), who wants them brought back to Northern Ireland for an investigation into whether criminal offences may have been committed by soldiers who used lethal force on Bloody Sunday in 1972.
At the centre of the case is the way the PSNI is conducting its historical probe into the deaths of 14 civil rights demonstrators in Londonderry.
Lawyers for the ex-soldiers, who live in England and gave evidence to the Bloody Sunday Inquiry (BSI) from the British mainland, argue there is a real danger their lives could unnecessarily be put at risk.
Arresting and transporting them "for what can only be described as administrative convenience" would be "unlawful, irrational and disproportionate", said James Lewis QC at a one-day hearing in November.
He said all the men were willing to be questioned on the mainland but intended to make "no comment".
Mr Lewis said the courts had already accepted there were many in Northern Ireland, and especially in Londonderry, who believed soldiers who opened fire were party to murder.
The Chief Constable's legal team rejected the claim lives could be at stake and countered: "The police are well used to dealing with the risks of people coming to Northern Ireland."
Jonathan Hall QC, appearing for the Chief Constable, observed in court: "Criminal investigations are unpleasant and unwelcome to those caught up in them, but are necessary for the rule of law."
The soldiers are asking Lord Thomas, sitting with Mr Justice Openshaw and Mrs Justice Carr, to block their arrests.
They say they are all willing to "voluntarily attend for an interview under caution" in England.
It was agreed during the hearing that further reports would be prepared to check whether one of the seven - Soldier 0 - was fit to travel.
Mr Lewis said, before the agreement, that the case of Soldier O, who had to travel long distances in a wheelchair after being left paralysed down his right side by a stroke, revealed that it appeared the PSNI had "an obsessive, mean-spirited intention to arrest at all costs".
The legal action follows the arrest of a former colleague in Northern Ireland - the first ex-soldier detained.
The arrest of the 66-year-old, who was held in Co Antrim and later released on police bail, was welcomed by relatives of those killed.
A petition calling for soldiers involved in Bloody Sunday to be granted immunity from prosecution has gained tens of thousands of supporters.
Thirteen people were killed by members of the Parachute Regiment on the day of the incident in Derry's Bogside.
Another victim of the shootings died in hospital four months later.
Northern Ireland police launched the murder investigation in 2012.
It was initiated after a Government-commissioned inquiry, undertaken by Lord Saville, found that none of the victims was posing a threat to soldiers when they were shot.
Following the publication of the Saville report in 2010, Prime Minister David Cameron apologised for the Army's actions, branding them "unjustified and unjustifiable".
In September, the PSNI told bereaved families they intended to interview a number of former soldiers about their involvement on the day.