The US Federal Communication Commission (FCC) showed no signs of backing down from a planned vote on T-Mobile US and Sprint’s proposed merger, even as calls for further review intensified.

In a letter, eight senators appealed to Chairman Ajit Pai to delay the vote and reopen public comment on the deal in light of concessions elicited from the operators by the Department of Justice.

The politicians argued “the risk posed to consumers if Dish Network fails to compete effectively or build its new wireless business is substantial”, adding further public comment to address potential harms is “appropriate and necessary”.

David Cicilline, chair of the House of Representatives’ Antitrust Subcommittee, in a separate letter, similarly urged Pai to extend the FCC’s review noting “there no urgency to forgo an opportunity for additional public comment”.

The comments echoed earlier calls for additional public comment from a number of industry associations and public interest groups.

However, an FCC representative told Mobile World Live there have already been “multiple public comment cycles” on the matter.

“This transaction has been pending in front of the Commission for more than a year…The time has come for Commissioners to vote and for this proceeding to be brought to a close.”

A date for the vote has not yet been set.