Oregon this week became the 15th state (plus the District of Columbia) to sign onto a lawsuit seeking to stop a T-Mobile/Sprint merger. The suit, co-signed by 16 attorneys general, argues that a merger between the country’s third and fourth largest carriers would greatly reduce competition in the wireless industry.

“It’s important that Oregon join other states in opposing the Sprint -T-Mobile merger,” said Oregon AG Ellen Rosenblum said in a statement. “If left unchallenged, the current plan will result in reduced access to affordable wireless service in Oregon — and higher prices. Neither is acceptable.”

Texas joined the suit earlier this month, marking one of only two Republican AGs who have signed onto the deal. Conservative voices have largely come out in favor of a merger, suggesting that by joining forces the new company (also named T-Mobile) would increase competition for AT&T and Verizon by getting a leg up in the race to implement 5G.

New York State AG Letitia James says the signee has added “momentum” to push against the merger, which was greenlit by the U.S. Department of Justice in late July.

“Oregon’s addition to our lawsuit keeps our momentum going, and ensures that there isn’t a single region of this country that doesn’t oppose this anticompetitive megamerger,” said James. “We welcome Attorney General Rosenblum to our 16-member coalition that now includes states representing almost half of the U.S. population. We remain committed to blocking the merger of T-Mobile and Sprint because it would bad for consumers, bad for workers, and bad for innovation.”