An EU report on net neutrality has been criticised by Internet freedom campaigners who say that it lacks strong policies to prevent a two-tier Internet.

The report, which was published by Digital Agenda Commissioner Neelie Kroes, says that the EU will investigate whether internet service providers (ISPs) are providing fair access to online services.

The investigation will cover both mobile and fixed providers and a report based on the findings will be published by the end of the year. The report could lead to a ban on ISPs from restricting access to data-heavy services during peak periods.

Kroes said, "At the end of 2011, I will publish the results, including any instances of blocking or throttling certain types of traffic. If I am not satisfied, I will not hesitate to come up with more stringent measures, which may take the form of guidance or even general legislative measures to achieve the competition and choice consumers deserve.

She added, "If this proves to be insufficient, I am ready to prohibit the blocking of lawful services or applications."

However, Kroes also said it is acceptable that some services need to be slower than others.

"A consumer’s experience is not affected if an e-mail reaches him a few seconds after it has been sent, whereas a similar delay to a voice communication would cause it to be significantly degraded, if not rendered entirely useless."

Internet speeds can be reduced by blocking or throttling of traffic. Blocking restricts access to certain services such as voice-over-IP, while throttling slows down certain types of traffic such as that of video streaming.

The EU’s annnouncement has reportedly disappointed net-neutrality campaigners. They have raised concerns that without stricter rules, ISPs may begin charging for unrestricted access to consumers and create a "two-tiered" internet. This, they say, will harm small businesses.

Internet freedom advocacy group La Quadrature du Net described the report as "extremely disappointing" and said that the report does not contain any strong policy to protect a free, open and neutral Internet.

The group added, Kroes was "hiding behind false liberal arguments that could undermine the freedom of communication and innovation in the digital environment."

Meanwhile, ISPs argue that traffic management is key to maintaining a quality service.

Earlier, British ISPs defended a two-speed Internet model at a ministerial summit on net neutrality chaired by communications minister Ed Vaizey.

ISPs – BT, Sky and Virgin Media – called for prioritising some traffic on their networks and block some. But the move could make some services out of reach for many users.

The ISPs argue that content providers should not be stopped from paying to get their traffic prioritised on the network if they want to do so. However, some content owners and digital activists say a two-speed Internet model would harm net neutrality in the long term.