Toiseach Bertie Ahern has been accused of snubbing the victims and survivors of the Omagh bomb by refusing to attend a ceremony marking the fifth anniversary of the blast.
The Co Tyrone town is due to hold an anniversary service next Friday, which includes a minute's silence, to commemorate the 29 people, including a woman pregnant with twins, killed in the Real IRA explosion on August 15 1998.
Patsy Gallagher, whose son Aidan was among those killed, last month sent letters to both Mr Ahern and Prime Minister Tony Blair inviting them to attend the event.
Mr Blair sent a personal letter to the Omagh grandmother expressing regret that he would not be able to attend Friday's ceremony.
In his letter, Mr Blair said: "Each day must bring painful memories to you and all those bereaved but these memories must be especially painful as the anniversary of that dreadful day approaches."
The Prime Minister revealed that he had asked Minister of State Jane Kennedy to represent him at the event before adding in a handwritten message: "I am very sorry I can't be with you."
However, the Gallagher family said they were hurt to receive a two-paragraph typed letter from a representative of the Taoiseach on Thursday – the day that
Real IRA chief Michael McKevitt was sentenced to 20 years imprisonment for his role in the paramilitary group.
The reply, sent by Mr Ahern's appointments secretary, read: "While the Taoiseach very much appreciates your thoughtfulness in extending this invitation to him, unfortunately he regrets that he is not in a position to accept as he will be away during that time."
Mrs Gallagher's husband, Michael, a founder member of the Omagh Support and Self-Help Group, said the letter was an insult to those affected by the bomb.
"The Taoiseach couldn't even sign a letter to us," he said.
"It is obscene that the Irish government is willing to send observers to the other side of the world to Columbia but the Taoiseach couldn't come to Omagh, which is just up the road from Dublin, for just one minute's silence."
He also accused Mr Ahern of "doing all kinds of moves" to avoid meeting relatives to discuss issues surrounding the Garda investigation as well as their civil action against five individuals, including Michael McKevitt.
"We have been sending letters to Mr Ahern for the past three years but he has always refused to meet us. This is what he thinks of us," Mr Gallagher said.
A government spokesman said the Taoiseach had always recognised the extreme importance of the issues surrounding Omagh.
He added that Mr Ahern, along with the Garda, were determined that there should be a "satisfactory conclusion" to the Omagh question.
