The DUP has asked Home Secretary Sajid Javid to meet families of those killed in the 1974 Birmingham pub bombings following the unmasking of the prime suspects in a TV documentary.
Former British soldier James Francis Gavin and convicted IRA bomber Michael Patrick Reilly were revealed last night as the two men West Midlands Police believe planted the bombs.
They exploded in The Tavern in the Town and the Mulberry Bush pubs just 10 minutes apart on November 21, 1974, killing 21 people and injuring more than 200 others.
Reilly's solicitor issued a statement on behalf of his client who he said "denies any allegation that he was involved" in the bombing.
He added that the claims were "untrue and without any foundation".
Just last week the Court of Appeal ruled in favour of coroner Sir Peter Thornton QC, upholding his right to exclude the identity of the perpetrators from a fresh inquest into the victims' deaths.
Julie Hambleton, who lost her sister Maxine (18) in the atrocity and who featured in last night's programme, welcomed the ITV Exposure investigation but said it raises more questions.
"It has taken a documentary maker to name the suspects behind what was the biggest act of mass murder carried out on the mainland in the 20th century," she said.
"The 'perpetrator issue' was our main legal point and now he has been named we hope it will force the coroner to expand the scope of the inquest, but what does that say about our country?".
Reilly has never been publicly named as a suspect, whereas Gavin - who died in 2002 - has been named in connection with the atrocity but never as the bomb-planter.
The Hunt For The Birmingham Bombers showed reporter John Ware confronting Reilly about the allegations outside a supermarket in Belfast, where he refused to comment. The documentary includes an interview with Ms Hambleton who has been fighting for justice for more than four decades.
"What do I want? Me, personally, I want the b******s who killed my sister and the other 20 to be brought to justice, short and simple," she said.
"We could have walked past him when we were in Belfast.
"When people ask you how'd you feel if you met them or saw them, you can never answer that question."
As a teenager in 1975 Reilly, who had been living in Birmingham at the time of the massacre, was interviewed by West Midlands Police but denied any involvement.
However, he did admit to bombing a number of local businesses in the city and was sentenced to 10 years in prison for conspiracy and causing explosions, and moved to Northern Ireland following his release.
The investigation relied heavily on the work of former Government minister Chris Mullin, who campaigned for the release of six men who were wrongly convicted for the bombing in 1975.
Hugh Callaghan, Patrick Joseph Hill, Gerard Hunter, Richard McIlkenny, William Power and John Walker became known as the Birmingham Six and eventually had their life sentences quashed by the Court of Appeal in 1991 in what was one of the most infamous miscarriages of justice in English legal history.
On two occasions Mullin interviewed a man who admitted to the bombing on the condition that his identity would never be revealed.
But by cross-referencing information in Mullin's book with police transcripts and birth records, interviewing eyewitnesses and a former IRA man, Mr Ware is convinced the evidence points to Reilly and Gavin.
Reacting to the new documentary, Ms Hambleton, who is a spokesperson for the Justice4the21 campaign, said all the relatives of the 21 victims welcome the revelation which has offered them hope of finally getting justice.
"We all remain puzzled over coroner Sir Thornton's reluctance to address the 'perpetrator issue' which they believe is a vital piece of the jigsaw," she said.
"This is the same coroner who has previously called on perpetrators to enter the witness stand which then led to prosecutions."
The tireless campaigner has spent the last two days protesting with other relatives outside the International Conference Centre in Birmingham which is hosting the Conservative Party Conference.
"We are fighting the biggest juggernaut in our country which is the British Government which for some reason is protecting those who murdered our loved ones," she said.
"Successive governments in the UK and Ireland have allowed mass murderers to walk free without fear of retribution which makes a mockery of even having a criminal justice system.
"What's the point if no one is prepared to put people through the prosecution process?"
Last night Sir Jeffrey Donaldson confirmed he will be requesting a meeting with Sajid Javid to discuss a number of issues relating to the inquest in light of the new allegations.
"I have listened to Ms Hambleton and will be requesting a meeting with the Home Secretary to allow her and other relatives to present their case," he said.
Ms Hambleton, who confronted a number of prominent MPs and Government ministers yesterday - including Nicky Morgan, Justine Greening, Anna Soubry and David Davis - praised Sir Jeffrey for vowing to help.
"Nearly 44 years later we are still fighting for our relatives who don't have a voice, but nobody in the British establishment or Irish Government wants to hear us," she said.
"They wish they could bury us alongside those who died because we dared to raise our heads above the parapet and ask questions and demand serious answers.
"But we are encouraged that some politicians, including Jeffrey Donaldson, are listening to us."