Lord Phillips of Sudbury told a Parliamentary meeting in London on Wednesday that neither backbenchers nor government ministers fully grasped the controversial Regulation of Investigatory Powers Act (RIPA), which was passed into law in 2000.
"The House of Lords gave more time to scrutinising RIPA than the House of Commons, and no one in the House of Lords fully understood all of RIPA's intricacies," said Lord Phillips, who described RIPA's passage through Parliament as a "nightmare".
According to Lord Phillips, several parts of RIPA are flawed -- including the oversight powers that should keep access to citizens' data in check.
The government is currently trying to get Parliament to approve changes to RIPA that will allow more government agencies to get access to details of individuals' telephone and Internet usage, and will also force service providers to retain this data.
These statutory instruments are being opposed by privacy groups who see them as a "snoopers' charter", and also by politicians who want the government to fix existing problems before widening RIPA's influence.
Baroness Blatch is concerned that government workers will be able to evade scrutiny and access details of Internet and mobile phone usage because of existing powers that she says the government is failing to tighten up.
"Under the law as it stands, if existing powers are not rescinded then people will be able to act within or outside the guidelines," said Baroness Blatch, who believes the government must tighten up some aspects of RIPA.
"There's a strong argument that government should go back and get it right," she insisted.
But according to the Home Office, it is important to press on and give more government agencies the right to intercept communications under RIPA, with the accompanying safeguards.
Simon Watkin of the Home Office rejected suggestions that these statutory instruments should be delayed. "It's better to do this now, and then iron out the flaws later," Watkin told the meeting.