The European Parliament has voted through legislation abolishing roaming charges and establishing principles for net neutrality, rejecting amendments that campaigners claimed filled critical loopholes in the legislation.

All online content should in theory now be treated indiscriminately by internet service providers, with a blog post by Günther H. Oettinger, EU Commissioner for Digital Economy and Society, saying that the vote had "guarantee(d) an open Internet".

However, a series of amendments to the bill were rejected by MEPs.

Net neutrality campaigners claim that without the amendments an open internet has not been delivered due to vaguely worded ‘exceptions’ in the text. Stricter rules had originally been proposed before member states opted for the current legislation.

A letter dated 25 October and signed by internet companies including Reddit and Netflix cites four main harmful practices that are allowed by the legislation as it currently stands.

One is fast lanes, allowing ISPs to offer better access to companies that can pay through the ‘specialised services’ exception.

Another is zero-rating, which allows ISPs not to count a consumer’s usage of certain applications against their monthly bandwidth caps. This could also be sold to the highest bidders as a service.

Class-based discrimination allows ISPs to define classes and speed up or slow down traffic in these classes.

Finally, the fact that ISPs can act to prevent ‘impending congestion’ on their network rather than just actual congestion means that ISPs can choose when they want to slow down traffic.

A statement from Joe McNamee, Executive Director of campaign group European Digital Rights said:

"The European Parliament has avoided making decisions on all crucial points. Now, national regulators will have to decide – on abuses imposed through ‘zero rating’, on rules on congestion management, on specialised services and so on.

"We will engage with BEREC and the Commission to provide clarity in the interpretation of the rules. Hopefully, the vagueness of the regulation can be fixed by BEREC’s guidelines and through diligent enforcement by national telecoms regulators."

Julia Reda, Member of the European Parliament for the Pirate Party, said: "Today’s vote on the Telecoms Single Market package in the European Parliament constitutes a broken promise both on the end of roaming surcharges and the establishment of net neutrality."

The rules have also drawn criticism from Tim Berners-Lee, the founder of the internet.

Meanwhile, the new ‘roam like at home’ roaming system will be implemented from June 2017, meaning that mobile devices can be used abroad at national rates.

This will come after a significant reduction in roaming charges in April 2016, when the roam like at home system will be introduced with a fee that users will pay, equal to the regulated wholesale cost paid by operators.