T-Mobile US and Sprint appear to be losing confidence that their deal to merge will be approved by the end of this month. The companies are working out a plan to extend a July 29 deadline to complete the $26.5 billion merger, Reuters reports.

The nation’s third- and fourth-largest operators announced their intention to merge almost 15 months ago in late April 2018. Although a formal vote hasn’t happened, a majority of the Federal Communications Commission has publicly stated their support for the merger. But the deal remains in limbo because the Department of Justice (DOJ) is concerned about the nation losing a fourth nationwide competitor.

Executives at T-Mobile US and Sprint have been negotiating with Dish Network and already agreed to numerous concessions, including the sale of Boost, but a deal and subsequent DOJ approval has yet to emerge. T-Mobile declined to comment on the reported deadline extension.

While the latest delay might be a nuisance for T-Mobile US and Sprint in the short term, an extension amid ongoing negotiations is a good sign for proponents of the merger, said William Ho, principal analyst at 556 Ventures. He remains confident that a deal will eventually be hammered out with Dish Network that satisfies the DOJ’s concerns.

“The broad overall arching goal of all of this is DOJ is holding out and saying this won’t happen until a fourth carrier stands up and becomes a competitor to the incumbents,” Ho said. With that, the agency has to consider more than upfront concessions and baseline infrastructure that could exchange hands, he explained.

Even with those initial attributes in place, along with Dish’s massive untapped spectrum portfolio, Dish could still fail and just end up selling its nearly 100 MHz of unused mid-band spectrum. “They’re going to need to invest tens or hundreds of billions of dollars into their network in the future to be a viable fourth carrier,” Ho said, adding that Verizon and AT&T are in a leadership position today because of large, sustained investments in their respective networks.

For all intents and purposes, Dish has emerged as the only outside party directly involved in the deal’s outcome. “I don’t think there are a whole lot of options out there,” Ho said. Dish Network co-founder and Chairman Charlie Ergen aggressively fought against the merger, but now he’s a central player and he’s wanted to be a player in wireless for at least a decade.

“He’s got to get in on this otherwise he’s got to sell that spectrum,” Ho said. “Does he stay relevant to be a bigger player or does he sell the spectrum, which everybody kind of expects because he’s a warehouser. This is his shot to get in. He’s been trying to get in for a long time so this is his shot at it.”

With each passing day, Roger Entner, founder and lead analyst at Recon Analytics, is less confident that a deal will occur. “I would blame this squarely at Charlie Ergen’s feet and he’s going to play this until he has them in a corner where they will agree to more than they should have. He will push them to the breaking point,” he said.

“For him it’s a win-win situation. He either squeezes them like a lemon or he makes a sale,” Entner said. “T-Mobile made one strategic mistake, that is to seek a deal with [Ergen].”