Bereaved families and survivors of the 1974 Dublin and Monaghan bombings have launched a campaign to speed up Britain's co-operation with the inquiry into the atrocities.
The British authorities have failed to provide any information to the Irish Independent Commission of Inquiry, nine months after a formal request by chairman Mr Justice Barron, family members have complained.
Three car bombs exploded in Dublin city centre on May 17th, 1974, killing 26 people, just 90 minutes before a second explosion in Monaghan killed seven.
More than 250 were injured in the attacks, which caused the single greatest loss of life in any one day of the Troubles.
For years there has been speculation that there was collusion between the Irish and British governments and the Loyalist bombers.
Today, the Justice for the Forgottengroup launched their drive in Dublin to speed up Britain's reaction, fearing the delay will deprive the inquiry of crucial information about the circumstances surrounding the bombings.
Over the next few weeks members will lobby members of the Dáil, place advertisements in the British press, and contact the French, Italian and American embassies in Dublin, as three of the victims were nationals of those countries.
Group spokesman Mr Cormac O’Dulachain said: "The British Government has known for nearly two years that this information was needed although the first formal request was made at the beginning of the year.
"In the past six months there has been a standard reply - that a hand trace of documents is going on in various departments and responses will be made.
"The main area where the inquiry has not been able to progress is in assessing what information the British Government has. The British Government, by delaying its response, is delaying the inquiry."
He added: "The victims and relatives feel that this response is deeply inadequate in light of Tony Blair's strongly expressed commitment to the global fight against terrorism since the events of September 11th."
Earlier this year, Taoiseach Bertie Ahern rejected allegations that the Government colluded with their British counterparts and loyalist paramilitaries in connection with the bombings as having no "factual credence".
The independent private inquiry into the bombings was established in 1999, initially under Mr Justice Liam Hamilton and then, following Mr Hamilton's death, Mr Justice Henry Barron, a former Supreme Court judge.
The Justice for the Forgottencampaign group describes the bombings as the biggest unsolved murder case in the history of the State.
Sinn Fein TD Caoimhghin O’Caolain today backed the call from the group.
The Cavan and Monaghan deputy said: "It is a scandal that no information whatsoever has been forthcoming from the British since the first request in January 2000. What have they got to hide?"
PA