However, the information regulator also said that it is unlikely to exercise its ability to fine companies up to £500,000 for non-compliance unless a breach causes "substantial distress".

The government was forced to revise the Privacy and Electronic Communications Regulations, which came into force in the UK on 26 May last year, to address a new EU directive that demands that businesses and organisations running websites in the UK need to get consent from visitors to their websites in order to store cookies on users' computers.

The ICO that it would give businesses a 12-month 'moratorium' period in which to get their house in order and to comply with the new regulation.

However, this period of preparation is due to finish on 26 May and the ICO will issue a letter of warning to the UK's 'top 50' websites, which is set to include central government departments.

"We will be writing to 50 key websites within the next few days. These will be websites were we see no signs of the right steps being put in place," said David Smith, deputy commissioner.