The European Parliament has waded into the turbulent waters of the US net neutrality debate with a letter urging the US Congress to block the latest moves by the country's Federal Communications Commission, which is trying to scrap net neutrality protections introduced during the Obama administration.

Signed by 148 Members of the European Parliament (MEPs), from across the European political divide, the letter highlights concern that anti-net neutrality legislation in the US could have a global impact, upsetting recent European efforts to enshrine net neutrality in law.

The letter was written by MEP Marietje Schaake, the vice president of the European Parliament's Transatlantic Legislative Dialogue, and appeared on her website late last week, taking aim at Donald Trump's administration for its efforts to repeal net neutrality.

"[The] Internet and the flow of data does not stop at the border and the FCC's decision has a global impact," wrote Schaake in a statement accompanying the letter. "A reversal of net neutrality rules by the United States is a threat to the open, free and fair Internet. The European Parliament has been a vocal proponent of net neutrality rules within Europe. Today we undertake action to also preserve the open Internet in the US."

Net neutrality is the somewhat hazy principle that all Internet traffic be treated equally. Supporters argue that network operators should not be allowed to block, throttle or discriminate in other ways against the services that are carried over their infrastructure.

But the issue is fiendishly complex and its regulation far from straightforward. One concern is whether operators of future 5G networks will be allowed to use a technique called "network slicing," whereby lots of different "virtualized" network services are provided over the same physical infrastructure. This would seem to be a violation of net neutrality, but the European Union has indicated that network slicing might be acceptable under its rules if an operator can prove it does not have a "detrimental" impact on other Internet access.

In a research paper issued last year, consulting group Analysys Mason warned the industry that "this process will have costs, and will slow down the process of deploying a specific network slice, hampering innovation in this area."

In the US, tough rules on net neutrality were backed by former FCC boss Tom Wheeler during the Obama administration, but Ajit Pai, Wheeler's successor at the FCC, is trying to roll these back, prompting an outcry from net neutrality supporters.

Pai's critics argue that scrapping net neutrality protections will shift the balance of power firmly toward the network operators and make the Internet services market a less vibrant and competitive place.

Last week, 21 state attorneys in the US filed a petition to challenge the FCC's anti-net neutrality rules, while Democrats were said to have secured the backing of 50 senators in the 100-person chamber for a repeal. (See Net Neutrality Moves Are as Futile as Trump's Comb-Over and Congress, Courts Ready to Rumble With FCC.)

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Opposition to the FCC's moves is now coming from overseas. In the statement on her website, Schaake noted that senators would have a 60-day period to block proposed changes following the FCC's publication of its new rules in the Federal Register in the next few weeks.

"In the senate, one vote now has the power to save net neutrality," said Schaake. "In addition to all 49 Democrats in the Senate, Republican Susan Collins of Maine has already pledged her support to the bill introduced by Senator Ed Markey of Massachusetts. The European Parliament is trying to sway at least one more Republican Senator to vote in favor of the bill."

The reversal of net neutrality positions in the US and Europe looks counter-intuitive. In the US, which coined the expression and previously saw net neutrality as an important right, broadband competition remains non-existent or very limited across much of the country. Analysts say this heightens the risk of discriminatory behavior by operators, because their customers have nowhere else to go. (See Net Neutrality Is Not a Rational Debate.)

By contrast, the earlier liberalization of Europe's telecom markets has given rise to several broadband operators per national territory, making any such abuses seem unlikely. Despite this, Europe's politicians have gone from ignoring net neutrality several years ago to making it a central part of their digital agenda.

 Iain Morris, News Editor, Light Reading