Although outgunned six-to-one in Washington lobby clout, Sprint Nextel chief Dan Hesse intends to out-shout AT&T in Congress to kill its takeover of T-Mobile for control of much of America’s cellphone business.

Hesse spoke at a wireless industry conference yesterday in Orlando and expressed fears that AT&T’s grip on the market would be “tremendous.”

“I have concerns it would stifle innovation,” Hess told Bloomberg.

Sprint Nextel said it would be trampled in the $39 billion merger of AT&T and T-Mobile, and left as a weak No. 3 behind Verizon. An expanded AT&T and Verizon would control 79 percent to the US wireless market.

Hesse will file complaints this week with a House panel that’s preparing a probe of antitrust issues in the proposed merger.

AT&T shot back that Hesse’s remarks were sour grapes.