Road-safety campaigners concerned about drink-driving have expressed dismay at the free bar for last Monday's official opening of the Drogheda by-pass.
Several hundred guests were at the event, including local councillors, council officials, National Roads Authority staff, construction engineers and the press.
A lunch with wine and the free bar were sponsored by four companies which built the road, which was formally opened by the Minister for Transport, Mr Brennan.
The chairman of the National Safety Council, Mr Eddie Shaw, said he was very concerned that there was a free bar at the celebrations.
He said "somebody obviously needs to ask themselves a question" about the appropriateness of the hospitality. The National Safety Council had "a simple view: don't ever drink and drive".
Dr Shane Butler, who lectures on addictive behaviour in social sciences at Trinity College, Dublin, said the issue went to the heart of the "confused approach of the Government to alcohol abuse".
"For 15 or 16 years, we have attempted to create a unified approach to alcohol abuse.
"It is not just the problems caused by alcoholics consuming large amounts of alcohol. Damage is also done by small amounts of alcohol. This type of thing provides a seal of approval."
A spokesman for Mr Brennan said the hospitality "should be seen very much as the contractors' end-of-project party".
"The Minister was a guest, he did not speak at the 'do' and his official functions were carried out at the official opening on the road."
The invitations were sent out in the names of Louth and Meath County Councils and carried the logos of both councils, the Department of Transport, the National Roads Authority, the National Development Plan and the EU Cohesion Fund.
