Federal Communications Commission (FCC) voted on Wednesday to approve the $26 billion merger between T-Mobile and Sprint, providing one of the final sign-offs on the deal.

The commissioners voted 3-2 along party lines, with Chairman Ajit Pai and the two Republican commissioners approving and the two Democratic commissioners voting against the deal.

The merger gained Justice Department approval in July, but it still faces a legal challenge from a team of state attorneys general seeking to block the deal.

T-Mobile and Sprint have argued that combining their companies, the third- and fourth-largest U.S. wireless carriers, would give them the ability to compete aggressively with AT&T and Verizon on 5G technology. But the state attorneys general involved in the lawsuit argue that the merger will reduce competition and drive up prices for customers.

Democratic FCC Commissioner Jessica Rosenworcel released a statement following the vote objecting to the approval.

“Overwhelming evidence demonstrates that the T-Mobile-Sprint merger will reduce competition, raise prices, lower quality, and slow innovation,” Rosenworcel said in a statement.

Remedies meant to reduce harm from the deal will not be enough to save consumers from the problems with this merger, Rosenworcel said.

The Justice Department, while approving the deal, ordered Sprint to divest certain interests including Boost Mobile and some wireless spectrum and T-Mobile must make its network accessible to Dish Network for seven years, among other stipulations.

T-Mobile and Sprint made commitments to the FCC to help deploy 5G networks across the U.S. if their merger was approved, such as agreeing to deploy a 5G network covering 97percent of the U.S. population within three years of the deal’s close.

“With 5G on the horizon, our dependence on wireless connectivity is bound to grow,” Rosenworcel said in the statement. “It’s not the time to count on ineffective deployment commitments, higher prices, and less vigorous competition to help the benefit of this new technology reach us all.”

There were no statements from the FCC commissioners who voted to approve the merger.

Sprint and T-Mobile face their next hurdle in December, when they go to trial with the state attorneys general.