Several MEPs have said they accidentally voted the wrong way on a key amendment of a new European copyright directive, meaning the most controversial aspects of the law might have been removed had they not erred.

The directive, which passed 348 to 274 on Tuesday, brings sweeping changes to copyright legislation across Europe, and will have an effect on the internet comparable in scope to 2018’s General Data Protection Regulation.

But the most controversial aspects of the law are two provisions, originally known as articles 11 and 13 and referred to as the “link tax” and “upload filter” respectively by opponents.

As passed, article 11 strengthens the copyright protections for news publishers against the re-use of their stories by internet companies, while article 13 greatly increases the responsibility internet companies have to prevent their platforms being used for copyright infringement.

Before the final vote on the directive, MEPs had a vote on whether to allow one last batch of amendments. If that vote had passed, a separate vote on articles 11 and 13 would have been allowed, in which MEPs could potentially have voted to remove the controversial clauses from the final directive.

The vote on whether to allow the batch of amendments failed by five votes, 312 to 317. But shortly after, in the European parliament’s official voting record, 13 MEPs asked for their vote to be recorded differently: 10 said they meant to support it, two meant to oppose it, and one meant to not vote at all. If those were counted, the result would have gone the other way. Despite the updated record of votes, however, the initial result still stands.

Since no vote was held on the specific amendments, there is no way to know whether MEPs would have removed the controversial provisions if they had had the chance to. But opponents of the copyright directive, and of articles 11 and 13, are angered by the error. “The vote they clicked on is the vote they got,” wrote Mike Masnick, of the tech culture site TechDirt. “It is frustrating beyond all belief that we ended up killing the open internet through tricking a bunch of MEPs by switching the voting order.”

Supporters argue that the laws even the playing field between large internet firms and traditional publishers, while opponents warn that the legislation risks creating an unfeasibly high barrier to publishing anything online, which will ultimately harm freedom of expression on the internet.