The chairman of the Federal Communications Commission (FCC), Tom Wheeler, wants the regulator to reject a request made by T-Mobile US for low-band spectrum to be set aside for smaller carriers in the next spectrum auction, while the Justice Department argues the auctions run the risk of frequencies being concentrated in the hands of the top two US operators.

Writing in a blog post on the FCC website, Wheeler said that “while some parties have petitioned the commission to increase the size of the reserve, the draft order on reconsideration I am circulating today would maintain the reserve size at the current level.”

“The draft order concludes that the current reserve size of 30 megahertz balances the desire to make low-band spectrum available to parties with limited holdings while facilitating competitive bidding for all auction participants,” he added.

Meanwhile, the Justice Department has issued a letter saying that the FCC should help small carriers gain access to spectrum otherwise AT&T and Verizon will end up with most of it, the Wall Street Journal reported.

The FCC should consider “the well-established competition principle that those with market power may be willing to pay the most to reinforce a leading position” says the letter written by William Baer, assistant attorney general for the antitrust division.

Earlier this month, Verizon hit back at claims from T-Mobile US CEO John Legere that it is trying to push the country’s number four player out of the upcoming US wireless auction, stating that “T-Mobile is more than welcome to participate in any auction the FCC holds”.