British Prime Minister Theresa May | Daniel Leal-Olivas/AFP via Getty Images BREXIT FILES INSIGHT Why EU may battle May over the Snooper’s Charter In finally passing her surveillance bill, Britain’s PM just made Brexit even more complicated.

Theresa May finally got her surveillance powers through the U.K. parliament — and with it, she has a whole new problem to overcome in the U.K.’s split from Europe.

Westminster gave a green light to the Investigatory Powers Bill on Wednesday, granting government security services wide-ranging powers to monitor people’s phones and computers.

The British prime minister set out the proposal, dubbed the Snooper’s Charter by critics, a year ago when she was home secretary and has twisted arms to get the bill through parliament. The bill allows government security services to hack people’s computers and smartphones, snoop on browsing history going back a year and track millions of devices simultaneously at the request of the home secretary. The government believes the legislation is needed to tackle organized crime and terrorism and May told parliament back in March that privacy is “hardwired” into the bill. However privacy advocates call it Orwellian, “the most extreme surveillance law ever passed in a democracy.”

The powers are fated to trigger a legal and political conflict between the U.K. and the EU over privacy – similar to the one Brussels has waged with the U.S. since Edward Snowden — revealed mass spying practices by the American government.

For now, U.K. companies can transfer data — everything from family photos to employee pay slips — within the EU. But once separated, the U.K. and EU will have to hash out a deal allowing companies to continue to transfer data across the Channel, much like the transatlantic “privacy shield.” Any future EU-U.K. deal will hinge on whether EU regulators believe their citizens’ privacy is respected under U.K. law. This doesn’t look straightforward.

European governments tend to take a much stricter view on privacy than their American counterparts. Once the Investigatory Powers Bill gains royal ascent and becomes British law, it is likely that Brussels regulators will be uncomfortable with the levels of mass surveillance permitted in the U.K., too.

If Brussels and the U.K. can’t reach an agreement allowing for the transfer of data between the two, it will be a lot harder for British companies to sell to Europeans and vice versa. U.K. trade relies heavily on services, particularly to the EU, which is its largest export market, accounting for 40 percent of trade. Cross-border services, such as international banking, require vast quantities of data to bounce back and forth over the internet.

Brussels has undertaken a crusade to export its vision on privacy and data protection across the world, devoting significant resources to negotiating new deals on privacy protections. In the past year, EU officials got the U.S. to start toning down its surveillance on EU citizens. The EU’s highest court has picked up the baton as defender of privacy as a fundamental right, striking down legislation that failed to protect internet users. European data watchdogs increasingly bite and bark at tech giants like Facebook and Google.

Britain may find itself next in line.

This insight is from POLITICO’s Brexit Files newsletter, a daily afternoon digest of the best coverage and analysis of Britain’s decision to leave the EU. Read today’s edition or subscribe here.