The directive, which will come into effect on 21 August, includes requirements on the information an online service provider must give a consumer, on the national law that will apply to online services, and on the information a consumer must have about the steps to take to conclude an e-contract.
E-commerce minister Stephen Timms said the e-commerce regulations are an important step towards making the UK "the best place in the world to do e-commerce".
"After extensive and detailed consultation, we have arrived at the right framework for UK business and consumers," he said. "[The regulations] will help to break down barriers across Europe and boost consumer confidence in online shopping."
However, the directive has come in for fierce criticism from industry bodies such as the Interactive Media in Retail Group (IMRG).
The group has estimated that the directive could cost UK businesses £11bn to implement; that compliance could take many months; and that it might be unworkable for mobile commerce and interactive television.
"E-commerce is meant to be quick, easy and efficient," said James Roper, chief executive of the IMRG. "This directive goes too far, demanding procedures that are unnecessary and not in line with best practice.
"It is government meddling, with all the art of a Neanderthal conducting brain surgery.
The directive was passed in June 2000 and was due to be implemented before 17 January 2000, but only three member states met this deadline.