The US Department of Justice (DoJ) questioned the legality of a bid by 16 state attorney generals to block T-Mobile US and Sprint’s merger plan, reported Bloomberg Law.

In a court hearing, the DoJ and operators said a lawsuit filed by attorney generals seeking to prevent the combination raised “serious constitutional concerns”.

The parties made the assertion during a hearing at the DC US District Court, which routinely reviews government merger settlements. The court is assessing the DoJ’s decision to approve the merger following commitments by the operators to divest assets to Dish Network, Bloomberg Law stated.

Regulator the Federal Communications Commission also moved to greenlight the merger, albeit by a slender majority.

The merger faced stiff opposition since being announced in 2018, with the states involved in the lawsuit citing concerns the deal will negatively affect jobs and consumer choice by reducing the number of major operators from four to three

During this week’s MWC19 Los Angeles event, Sprint Business president Jan Geldmacher said he expects the merger to be pushed through at a court showdown with the states in December.

T-Mobile, meanwhile, continued a campaign to overcome the attorney generals’ objections: this week, Colorado became the second state to drop out of the lawsuit following commitments by the operator around 5G coverage and pricing.