The analysts at Wall Street Research firm Raymond James today lowered their odds on the Sprint and T-Mobile merger from 80% to 55%. In a note to investors, the analysts cited "the increased opposition to the deal that seems to be focused on the potential impacts on the prepaid, wholesale, and rural markets, and the likelihood that the decision process for states like California will drag into 3Q with the potential that some state Attorney Generals will also become more vocal."

Separately, Sprint and T-Mobile extended their deadline for completing the deal to July 29. The companies didn't provide any other details related to the extension, noting only in their SEC filing that "the completion of the Merger Transactions remains subject to regulatory approvals and certain other customary closing conditions."

However, the head of the Justice Department's antitrust division said he has not yet made a decision on the transaction. "I have not made up my mind," Makan Delrahim said in an interview with CNBC. "The investigation continues. We've requested some data from the companies that will be forthcoming. We don't have a set number of meetings or a timeline."

Delrahim's comments are noteworthy in light of a report from the Wall Street Journal last week that regulators at the DoJ weren't going to approve the transaction as it was currently structured.

Executives from T-Mobile maintained a positive outlook on the agreement last week during the company's quarterly earnings conference call with investors. CEO John Legere said he was "optimistic and confident" that the deal will be approved by June. He also said the company has reached an agreement with New York regulators and that it continues to work to reach an agreement with California regulators on the deal.

However, the analysts at Raymond James wrote that the transaction faces increasing headwinds. "We believe there are still currently paths to gain approval," they noted. "But, the time for proposing concessions, or changing the deal structure is at hand, as the longer the process extends the more wrapped up it will become in the next presidential election cycle and the lower the odds of approval would become. We think offers to divest a prepaid brand, such as Boost, extend wholesale agreements with cable and rural wireless operators, and commit to verifiable 5G coverage and service levels to rural areas/low-income households/underperforming schools would be viewed favorably by both political parties."

Interestingly, the analysts also pointed out that Sprint won't get anything but a roaming agreement from T-Mobile if the proposed merger does fall apart. They noted that's a very different situation than what T-Mobile faced when its proposed merger with AT&T fell apart in 2011. At that time, AT&T paid T-Mobile a $3 billion breakup fee and gave it a significant amount of new spectrum. "That means that Sprint does not get cash or spectrum, and would be in a very tenuous position in a capital-intensive industry," the analysts wrote.

At issue is a merger that would essentially remake the US wireless industry by creating the nation's third largest wireless network operator with significant spectrum holdings for 5G.

— Mike Dano, Editorial Director, 5G & Mobile Strategies, Light Reading | @mikeddano