The Law Society of Scotland fears the Data Retention and Investigatory Powers Bill is being pushed through too quickly without being subjected to the proper level of scrutiny.
The society, which represents the country's lawyers, has also raised questions over the legality of the bill as the European Court of Justice has already thrown out similar EU legislation.
The bill, which the UK Government claims will help battle terrorism and serious crime, has already attracted criticism from the Scottish Government, as well as privacy campaigners.
It aims to force telecommunication companies to store data on their customers, such as calls made, to whom and at what time.
Tim Musson, convener of the Law Society's Privacy Law Committee, said: "The bill will reinstate powers to the police which are based on legislation derived from a European Union Directive which the European Court of Justice has said is invalid.
"We have substantial concerns that this legislation is going through the UK parliament at such a speed that it will not be subjected to the level of scrutiny that each parliamentary stage usually requires.
"In April, the European Court of Justice handed down a ruling that communications companies did not have to adhere to the 2006 Data Retention Directive, which states that they should keep data on their customers for between six months and two years.
"This is an important ruling and the proposed legislation deserves the appropriate scrutiny in order to maintain public confidence.
"There will certainly be many people asking how, if the EU Directive has been declared illegal, the new legislation can be legal."
The UK Government was forced to act after a ruling in April that a European Union data retention directive, implemented by Labour in 2009, was invalid because it interferes with the fundamental right to respect for private life.
Police and security services raised fears that, without this legal underpinning, companies would start deleting data crucial for investigations into a range of serious crime including terrorism, child pornography and drug trafficking.
The Scottish Government has already hit out at the "lack of prior consultation" from UK ministers.
Privacy campaigners have also warned it impinges on the basic principle of a free society that you do not snoop on people who are not suspected of anything.
The bill, being pushed through in ten days, is expected to pass its final stage today.