Opponents of Sprint and T-Mobile US’ proposed merger seized on recent fraud allegations against the former, arguing regulators should halt a review of the deal until a probe is complete.

In a petition, a coalition of nine organisations pressed the Federal Communications Commission (FCC) to delay an expected vote on the merger until claims that Sprint illegally accepted payments for 885,000 inactive subscribers on the government’s Lifeline subsidy programme are fully investigated.

The coalition added FCC precedent “is clear that a company cannot sell or transfer a licence when the company’s fitness to hold a licence is at issue” and urged the regulator to reopen public comment on the matter, arguing the review process had been “highly unusual”.

In addition, the group noted FCC chairman Ajit Pai and two other commissioners declared their support for the merger before the conclusion of a review by the agency or a separate assessment by the Department of Justice (DoJ). The coalition reiterated previous assertions that conditions imposed by the DoJ “raise new and important public interest and competition issues related to execution risk” which warrant public input.

The petition was backed by the Communications Workers of America; Rural Wireless Association; NTCA – The Rural Broadband Association; and Consumer Reports, among others.

FCC officials previously brushed off calls for further comment and review, noting there had been “multiple” input cycles. Pai in August announced plans to hold a vote on the matter, but is yet to set a date.

Sprint and T-Mobile still face a lawsuit from state officials seeking to block the deal. Pennsylvania became the 17th state to join the case in September.

Seven states have come out in favour of the merger.