Progressive freshman Democrat Rep. Rashida Tlaib (D-MI) is leading an effort in the House to block the proposed $26 billion merger deal between T-Mobile and Sprint, according to The Hill.

Tlaib is reportedly planning to send letters to Federal Communications Commission chair Ajit Pai and the Justice Department’s antitrust head Makan Delrahim later today asking that the two refuse to approve the merger. Approval from the FCC and DOJ are necessary for the merger to go through. According to The Hill, 36 other progressive Democrats like Reps. Alexandria Ocasio-Cortez (D-NY) and Pramila Jayapal (D-WA) are anticipated to sign onto the letters.

Last month, Senate Democrats sent similar letters to both Pai and Delrahim about the deal. Presidential hopefuls like Sens. Amy Klobuchar (D-MN) and Bernie Sanders (I-VT) signed the Senate letters pressuring the officials to reject the merger. “We are deeply concerned that the merger of Sprint and T-Mobile in particular will eliminate competition that has been shown to benefit consumers and stifle the emergence of new carriers,” the senators said.

Opponents to the merger argue that it will drive up wireless plan prices by shrinking the nation’s carrier pool from four major companies to three.

In a blog post last month, T-Mobile CEO John Legere reiterated all of the same talking points he’s been making over the past year, saying that the merger would be the only way for both T-Mobile and Sprint to deploy 5G nationwide. Despite the talking point, Sprint has already moved to be the first national carrier to introduce the technology into its networks.

Lawmakers have no say in whether a merger is approved or not. The FCC and DOJ are the only two bodies required to approve the merger before it proceeds.

T-Mobile has been in hot water with lawmakers after The Washington Post reported that company executives were paying for lofty hotel space at the DC Trump hotel following the merger announcement. Earlier today, T-Mobile admitted to the reporting and said that the company had spent nearly $200,000 at the Trump hotel over the past year or so.