Senate Democrats pressed Federal Communication Commission Chairman Ajit Pai on Wednesday to delay a vote on internet neutrality rules, arguing in a letter that the repeal of the regulations could be devastating for K-12 and higher education.

The letter, organized by Sen. Patty Murray, D-Wash., and signed by more than 20 of her Democratic colleagues, comes a day before the FCC is set to vote Thursday to undo Obama-era regulations that ensure companies that provide internet access cannot favor certain websites over others by choosing which load faster – rules that are widely known as net neutrality.

“By overturning the commission’s current rules that preserve net neutrality and prevent internet service providers from blocking, throttling, or otherwise privileging lawful content, we fear that the Draft Order could harm our nation’s students and schools – especially those in rural and low-income communities,” they wrote. “We urge you to delay this monumental decision to dismantle net neutrality until you have fully examined the Draft Order’s impact on our nation’s students and their ability to learn.”

Pai has argued that the rules are too burdensome and that they stifle innovation. Repealing net neutrality, he has said, is imperative to return to a “free market-based approach” to the internet.

But Democrats, along with a host of K-12 and higher education groups, are worried that repealing the regulation would disproportionately hurt students in rural areas, which account for the majority of schools that still lack high-speed fiber optics, as well as the estimated 5 million students whose only access to the internet is in schools.

“By rolling back the FCC’s current prohibitions against blocking, throttling, and paid prioritization, the Draft Order could lead to a tiered and compartmentalized internet, and whose characteristic openness is limited to those students, schools, and institutions who can afford it,” they wrote.

The letter underscores the significant strides in improving high-speed connectivity, largely thanks to the federal E-Rate program, which provides funding for schools and libraries to connect to the internet and which the FCC, under the Obama administration, voted to modernize in 2014 with a $1.5 billion boost in funding.

Indeed, in four years, the number of students with access to high-speed internet has increased tenfold. In 2013, only 4 million students had access to broadband that provided internet fast enough to allow for digital learning in the classroom. Now, four years later, that number has catapulted to 39.2 million.

The letter also details potential pitfalls in the higher education space at a time when online class enrollment has never been higher: As of the fall of 2015, more than 6 million students enrolled in at least one online course, representing about 30 percent of enrollments, compared to less than 10 percent in the fall of 2002.