Many in Brussels expect a protracted battle as the tech industry spends more than ever on lobbying. And while there is strong political momentum for new regulations, the guidelines may not be approved for years as the debate could stall at many stages of the negotiation.
Mr Lewis said the debate will be a test of the United States-European Union relationship, which has been tense during the Trump administration on issues such as digital taxes. A trade group representing major American tech companies, the Internet Association, has already complained to US officials in Washington about the new European rules.
Veterans of past European debates said the challenge will be to translate the law's lofty ambitions into strong enforcement, an area where previous E.U. Politics fell short.
Europe's pioneering online data protection act for 2018, known as the European Data Protection Regulation, has been criticized for failing to deliver on its promise due to lack of enforcement. Despite a limited budget, Ireland is responsible for regulating all tech companies with European headquarters within its borders – including Facebook, Apple, and Google – and on Tuesday imposed only the first major tech platform fined Twitter, more than two years after the entry into force of the law.
"It's important for the E.U. to put their priorities into practice, not just talk about them," said Marietje Schaake, a former member of the European Parliament who now teaches at Stanford University.
The European debate is already turning some companies against each other. On Monday, Facebook released a statement calling on European regulators to take action against Apple. This is part of an ongoing feud between the two companies over Apple's App Store policies, which Facebook said "harms developers and consumers."
Raegan MacDonald, head of public order in Brussels at the Mozilla Foundation, which operates the Firefox browser, described the effort in Europe as a once-in-a-lifetime opportunity, particularly the transparency rules that would provide important insights into how the company works.