He resigned from the Fianna Fáil in 2000 following a finding by a party standards committee that he had failed to co-operate with its investigation into planning irregularities, and subsequently came into conflict with the Mahon Tribunal.
[3] Lawlor regained his Dáil seat again at the 1987 general election, and was appointed Chairman of the Oireachtas Joint Committee on Commercial State-Sponsored Bodies.
[4] Lawlor was one of a number of local councillors who were called as witnesses before the Mahon Tribunal investigating planning and payments in County Dublin.
On the eve of publication of the committee report in June 2000, Lawlor resigned from the party; however he continued to support the government in Dáil Éireann.
In what the Irish Independent described as "one of the most sensational days in the House", Lawlor was released temporarily by the High Court to mount his own defence during an hour-long debate.
Taken into Leinster House in a prison van, Lawlor sat alone at the rear of the Chamber while the five party leaders, in turn, called on him to step down.
High Court president Justice Joseph Finnegan granted the request but laid down strict conditions on Lawlor's release, saying he was to be taken from Mountjoy to Leinster House, stay for the debate and then be returned to jail.
The driver, a Russian businessman, Ruslan Suleymanov, was fatally injured, when he swerved the car to avoid a man and a woman who ran out onto the road in front of it.