Families of those shot dead during an Army operation in west Belfast are considering a legal challenge against a Government decision to reject an independent re-examination of the killings.
Secretary of State Theresa Villiers ruled out their call to establish a review panel to assess the evidence on the Ballymurphy massacre, claiming it would not serve the public interest.
Ten people died after being shot by soldiers, among them a Catholic priest and a mother-of-eight, over three days of gunfire in August 1971. Another man died of a heart attack following an alleged violent confrontation with the troops.
Families reacted furiously to the decision, while Taoiseach Enda Kenny expressed his disappointment.
Briege Foyle, whose mother Joan Connolly was killed, ripped up Ms Villiers' letter informing her of the rejection at an emotional Press conference in west Belfast.
"We will fight for this until we die and then our young family will come in and they will fight for it, we will get our day," she said.
"Theresa Villiers is just a puppet for David Cameron. But David Cameron, we are coming – we are coming to 10 Downing Street and we are going to let you know that we are not going anywhere."
Lawyers for the families are now considering a potential judicial review of Ms Villiers' decision.
As with Bloody Sunday in Londonderry six months later, members of the Parachute Regiment were involved in the shootings in Ballymurphy.
A new inquest into the 10 deaths caused by gunfire was ordered by Attorney General John Larkin QC in 2011.
The families have also campaigned for a review panel to be set up by the Government. They wanted the probe modelled on the one that re-examined the Hillsborough football disaster.
They suggested the panel could have been chaired by former Police Ombudsman Nuala O'Loan.
The shootings took place as the Army moved into republican strongholds in west Belfast to arrest IRA suspects after the Stormont administration introduced of the controversial policy of internment without trial.
Soldiers claimed they had come under attack and returned fire. But relatives have demanded an acknowledgement that their loved ones were wrongfully killed.
Ms Villiers said the decision had been made after careful consideration. "I have met the families who lost loved ones in Ballymurphy and I was very moved to hear their personal stories of pain and loss, and by their shared sense of determination," she said.
"I have taken time to consider their proposal for an independent review panel, which I received last summer.
"In my view, the balance of public interest does not favour establishing an independent review. I do not believe that such a review would provide answers which are not already in the public domain or covered by existing legal processes.
"In reaching this decision, I have sought to balance the strong and clear views of the families with the need to ensure that existing legal mechanisms can continue to carry out their functions without being impeded by an additional process. That includes the ongoing coroners' inquests."
John Teggart, whose father Daniel was one of those killed, said the Government had treated them in a "disrespectful and shameful manner".
Mr Kenny, who had backed the families' call for a review, said: "Notwithstanding this setback, I hope that it will still be possible to find a way for the families to get the truth and to vindicate fully the good names of their loved ones."
"The families have a message for David Cameron – when will you stop harbouring the murderers in the ranks of the British army?
"No-one should be above the law. Are the 11 people who lay in their graves of different worth because they are Irish citizens? We families will not be deterred by this disgraceful decision, in fact we will step up our campaign, shaming your government and your hypocritical policies."
John Teggart, son of a Ballymurphy victim