Members of the US Federal Communications Commission (FCC) blasted the Department of Commerce (DoC) for obstructing efforts to free new spectrum, warning such activity threatens 5G progress.

The FCC and other federal agencies recently clashed over whether commercial use of the 24GHz band would interfere with critical government weather forecasting sensors.

But in testimony before a congressional oversight committee, Commissioner Michael O’Rielly explained disagreements extend “to every other band” under discussion.

“They want to come back and retest and re-challenge decisions we are making. That’s very problematic.”

An auction of licences in the 24GHz band closed in May: spectrum in the 37GHz, 39GHz and 47GHz bands will be sold in December.

FCC Chairman Ajit Pai revealed there are some members of the federal government who believe 5G deployments may interfere with official uses. One department in particular had been “very active in trying to undermine the US position in international negotiations and make it more difficult for us to free up spectrum in 5G”.

He expressed frustration the DoC was “blocking our efforts at every single turn”, adding it has become increasingly difficult for the pair to work together following the abrupt resignation of a key telecom adviser last month.

Commissioner Jessica Rosenworcel called the public disputes “embarrassing”, warning they could undermine future 5G auctions and US negotiations at the ITU World Radiocommunication Conference in October.

Pai requested Congress pass a resolution demanding the development and deployment of 5G as quickly as possible.

“That one sentence resolution alone would give us, I think, some momentum.”