T-Mobile US was ordered to face a lawsuit over its acquisition of Sprint in 2020, as a US judge sided with AT&T and Verizon subscribers who filed a class action arguing the deal hurt competition and led to increased prices.

The case was filed by seven AT&T or Verizon subscribers on behalf of millions of consumers who the claimants say were impacted by the $26 billion deal.

Plaintiffs described the deal as “one of the most anti-competitive” in history and called for a range of penalties, including an undoing of the takeover.

A judge found plaintiffs had plausibly argued higher prices in the US market “flowed directly” from completion of the deal, showing the reduction in competition resulted in AT&T and Verizon charging “higher prices than they would have otherwise”.

AT&T and Verizon are not directly involved in the case.

T-Mobile’s legal team described the class action as unprecedented and speculative.

Reuters reported the team argued consumers should “switch to T-Mobile, not sue it” because they are dissatisfied with its rivals pricing.

T-Mobile made numerous commitments around pricing, competition and jobs to alleviate competition concerns.