New rules that have been designed to protect people from intrusive cookies could have the opposite effect and give internet users a huge headache.

Under the European Union's Telecoms Package of reforms, people will have to personally approve every cookie that attempts to download to their PC. An exception exists where the cookie is "strictly necessary" for the provision of a service "explicitly requested" by the user.

The change to the law raises the possibility that people visiting websites for the first time will be plagued with pop-up windows, and will have to spend time manually approving every cookie that the site tries to download.

One web page alone can contain multiple cookies, as can adverts on those web pages.

Advertising trade bodies, such as the Interactive Advertising Bureau (IAB) Europe have claimed that a person’s browser settings will imply prior consent.

A 'recital', or non-binding preamble, to the text in the reforms does say that some cookies can be consented to this way.

However Struan Robertson, technology lawyer at Pinsent Masons law firm is not so sure.

"I don't think browser settings achieve strict compliance with the rules. Most accept cookies by default and the user has to actively change the settings to block cookies, and I suspect that most people do not.

“Both the recital and rules refer to the need to give "clear and comprehensive information" before cookies are stored. Browsers can't give you that information because they can't tell you how a site will use the cookies it serves - so you need to get that information from the website privacy policy.

“The Directive is worded such that you should get this information before the cookie is served - not afterwards,” he said.

Cookies are small text files placed on a PC when a person visits a website. They have various aims such as ensuring relevant content is shown when a person re-visits a site, or to help with online sales and services

When rejecting cookies, this can have an adverse affect on some sites; for example some shopping carts or login systems won’t work without them.