"We will vindicate our father's name and character, " claimed a defiant Niall Lawlor last night.

"Liam Lawlor was not a complete ogre as has been portrayed by the tribunal.

He was a great guy, a fantastic father and a great friend."

After a decade that has been "the most horrific and stressful time" in the life of the Lawlor family, they are determined to fight to restore Liam Lawlor's reputation.

"We would not be taking this case if we were going to give up the fight against the tribunal, " Niall Lawlor said.

"We are not looking to stop the tribunal. We want to get in there and set the record straight. I don't want my father's legacy to be singularly tainted by the manner and conduct of the tribunal and the perception it left."

The father of two added:

"We want his legacy to be portrayed in a fair and balanced account of his political life and his character as a man. He was a very fair, caring and generous individual and that stretched well beyond his family. . . his constituents would vouch for that."

Lawlor claims that the Mahon tribunal "turned up the heat" on his father after he took them to the High Court over the tribunal's terms of reference in 1999.

"It was open season from then on and it is not going to be open season on my mother. That is something that we are not going to allow."

The Lawlors are extremely bitter that the last years of the former Fianna F�il TD's life, before he was killed in a car accident in Moscow in October 2005, were "destroyed by the tribunal".

"It had a huge effect on him and the unfairness of it all really took its toll. It was such a vindictive and insurmountable maze to be in, " said Niall Lawlor.

"After my father's death, I came back to the US to continue my career in finance and it is difficult knowing that mum is alone trying to deal with the trauma of the sudden loss as well as the tribunal putting pressure on her.

"She is living under the fear of the tribunal exacting a judgement mortgage to sell the family home from under her.

"It has been a very complicated and huge worry for her and the rest of the family. I don't think Hazel Lawlor deserves to be dragged through this and we won't let her be treated in the same way as they treated my father."

A Mahon tribunal motion seeking to dismiss the Lawlors' action will be heard on Wednesday.