Europe's internet is about to go on trial, and activists are very worried about its future.

On Tuesday, European lawmakers will vote on a proposal that aims to protect net neutrality — the principle that internet service providers (ISPs) should treat all web traffic equally, without discriminating against some services in favor of others. The proposed legislation broadly prohibits ISPs from charging websites for faster connections, ostensibly keeping the web open and equal. But it also includes major loopholes that could undermine the very principle that it claims to protect.

If lawmakers approve the regulations tomorrow, they will become law across the EU, replacing existing net neutrality laws already implemented in the Netherlands and Slovenia. And if the proposal is passed without amendments, experts say it could have devastating impacts on innovation, market competition, and consumer privacy.

"Europe will have far weaker network neutrality rules than the US."

"Europe will have far weaker network neutrality rules than the US, and the European internet would become less free and less open," writes Barbara van Schewick, a Stanford law professor and director of the Stanford Center for Internet and Society. (The US Federal Communications Commission passed net neutrality regulations in February.)

Tuesday's vote comes after two years of negotiations among the 28 member states in the European Union. The European Parliament approved rules that would strengthen net neutrality in April 2014, but making them law requires agreement among the Parliament, the European Commission, and the Council of the European Union, a body of 28 EU ministers. The Council took issue with some of the key provisions laid out in the Parliament's initial plan, and proposed amendments that would allow for crucial exceptions. A compromise proposal was announced earlier this year, and its current form includes troubling provisions.

Among the most contentious is a clause that would allow so-called "specialized services" to pay to have their content delivered faster. The idea is to protect IP services that demand high-quality connections and use the same access network as the internet but are not open to everyone, such as self-driving cars or remote medical operations. But critics say the current parameters are too broad, effectively allowing ISPs to create the kind of two-tiered system that net neutrality is designed to prevent. There are concerns over a similar loophole in the FCC's net neutrality regulations, and companies have reportedly sought to exploit it for fast lane access.

A call for clarity

"Large corporations that pay to be in the fast lane will have higher costs, so we the customers will be forced to pay higher prices for their products and services," van Schewick wrote in a lengthy Medium post last week explaining the major loopholes and their implications. "Small businesses that are unable to pay will be shut out of the market."

European telecoms have argued that tighter regulations on specialized services would hinder their business, and ultimately harm the consumer. "If restrictive rules on traffic management and specialized services are approved, we risk to worsen the user experience and to reduce the overall growth and job creation potential of Europe's digital economy," Steven Tas, head of the industry group ETNO, told Reuters earlier this year.

Another provision pertains to zero-rating, a practice whereby the use of certain services or applications doesn't count against a consumer's monthly data allowance. The proposal both allows for zero-rating — which allows ISPs to favor one service over another — and leaves no room for member states to regulate it. (Netflix came under fire for a zero-rating scheme in Australia, as did Facebook's Internet.org initiative in India.)

ISPs would also be allowed to manage traffic congestion if it's "impending," though the proposal doesn't offer a clear definition of "impending." Net neutrality advocates acknowledge that ISPs should be able to manage traffic at times of congestion, and the proposal outlines clear procedures on how to do that. But the fear is that the provision could be exploited to slow down or prioritize certain services at any time.

Then there's the issue of class-based discrimination, which allows ISPs to speed up or slow down traffic depending on the type of data being transmitted. A video call, for instance, may be optimized because it demands fast connections, whereas email traffic may be allowed to lag. The European Parliament's proposal allows ISPs to engage in this discrimination at all times, which could distort competition. It also threatens encrypted data, which cannot be classified because it cannot be read. Activists say that if ISPs can't classify encrypted data, they'll just slow it down by default. And that could have serious implications for consumer privacy at a time of heightened concerns over government surveillance.

"They need to be made aware of what is at stake."

"If you delay encrypted traffic, then it's very likely that less traffic will be encrypted," says Rejo Zenger, a privacy advocate at Bits of Freedom, an Amsterdam-based digital rights organization. "That's something we don't need... The development and use of high-grade encryption should be supported wherever possible."

Europe's net neutrality proposal is one half of a larger legislative package; the other aims to abolish mobile roaming charges across the EU. There has been broad agreement on eliminating roaming charges, and the initiative has largely overshadowed the net neutrality debate. But that's changed in recent weeks.

A campaign called Save The Internet is calling for web users to contact members of parliament and urge them to adopt amendments that would close the legislation's most problematic loopholes. On Sunday, TechCrunch reported that van Schewick is penning an open letter to European lawmakers, which will be signed by "leading tech companies."

As Zenger points out, amendments that would close, or at least clarify the loopholes are already on the table, and will be up for debate on Tuesday. Now, he says, it's just a matter of raising awareness among Europe's elected officials.

"They need to be made aware of what is at stake," he says, adding that "if the loopholes are not fixed, then practically, there will be no net neutrality in Europe."