EU regulators on Tuesday adopted a strict interpretation of rules limiting how telecoms firms like Vodafone and Orange can prioritise some types of internet traffic, aiming to protect the principle that all web traffic be treated equally.
The guidelines on net neutrality were welcomed by internet activists as ensuring the web remains an open platform and not a two-speed highway, benefiting only companies with deep pockets that can pay for prioritised delivery.
"Because of this law, telecom companies won't be able to sell a first-class Internet to the mega-rich while the rest of us travel coach," said Luca Nicotra, a senior campaigner for citizens' group Avaaz.
The European Union adopted its first-ever net neutrality law last year and the latest guidelines will help determine how regulators enforce those rules.
The telecoms industry has been seeking to increase revenues by offering specialised services that need a guaranteed level of quality, to offset declining turnover from its traditional telephony business.
Companies had pushed for leeway allowing them to prioritise some types of data over others, but under the latest guidelines they will only be able to offer so-called specialised services - such as connectivity for driverless cars and internet-connected devices - over dedicated network capacity if it is "objectively necessary" and only if it does not negatively affect the Internet.
"We encourage national regulators to maintain the pragmatic and flexible approach that was intended by the EU regulation and that has served customers, innovation and industry in Europe well to date," said a spokesman for cable operator Liberty Global .
Services such as high-quality voice calling on mobile networks, live television delivered over the Internet and remote surgery, or telesurgery, are likely to be allowed as specialised services, according to the guidelines.
The telecoms industry said it was essential to avoid "restrictive interpretations" of the net neutrality law.
"Let's make sure the implementation of net neutrality rules does not hamper new applications and services," said Lise Fuhr, director general of ETNO, a telecoms lobbying group representing operators including Deutsche Telekom, Telefonica and Telecom Italia.
Regulators also limited the extent to which telecoms operators may exempt some applications, for example Facebook, from a customer's data usage, a practice known as zero-rating.
© Thomson Reuters 2016