Accusing Justice Minister Michael McDowell of acting purely for political reasons, Trinity's Reid Professor of Law Ivana Bacik said some elements of the made no legal sense whatsoever.
"It's nonsensical and another area where peoples civil liberties are under threat," she said, branding the legislation a knee-jerk response to public perception.
"I know there are serious issues about drinking and abuse of alcohol but I don't think the way to tackle them is through restricting opening hours or through creating new criminal offences," she said.
The Bill, which is expected to be passed this week, was also attacked by the National Youth Federation (NYF), which called for the withdrawal of the Bill's proposal that all those under the age of 21 carry ID cards in pubs.
NYF chief executive Diarmuid Kearney said the measure was blatantly discriminatory. "No such restrictions are to be imposed upon those actually convicted of drink driving, assault or being drunk and disorderly," he said.
Apart from the ID measure the Bill includes proposals to:
Make being drunk in a public house a criminal offence.
Transfer all discrimination cases involving pubs from the Equality Authority to the District Courts.
Bring Thursday closing time back to 11.30.
Ban all those under the age of 18 children in bars after 8pm.
Ms Bacik questioned Mr McDowell's motivations. "The underlying rational of the Bill that you can throw new offences at the problem or restrict opening hours and make it go away is faulty," she said.
"The political imperative was to be seen to do something about drink. When something like this becomes an issue there's a pressure on politicians to move quickly to do something about it but inevitably you tend to get bad legislation as a result," she said.
The proposal to make being drunk in a public bar a new offence was impossible to enforce and open to abuse, she said.
"There's no defence built in. Somebody could have a very good reason for entering a pub while drunk. They may be looking for coffee or to get a friend to drive them home," she said.
The proposed legislation has also drawn criticism from an assortment of organisations including the Irish Hotels Federation (IHF), the Irish Nightclub Industry Association and the Licensed Vintners Association.
The IHF has made it clear that the obligation that everybody under the age of 21, unless accompanied by a parent or guardian, carry documentary evidence of age when in the bar area of hotels is and unworkable.
But the Bill was defended by a spokesman for Mr McDowell who said the measures were intended to cut down on violent and antisocial behaviour resulting from alcohol abuse.
"All the measures were recommended by the Liquor Licensing Commission and are there to cut down on this problem," he said.