As 71 House members urged the U.S. Air Force on Friday to re-bid an aerial refueling tanker contract, U.S. Sen. Jeff Sessions, R-Mobile, blocked legislation aimed at doing exactly that.

In a news release, Sessions said he had put a "hold" on a bill introduced Thursday that would bar the military from spending any money on the tanker contract unless it either gives the work to Boeing Co. or else holds a new competition under conditions tilted in favor of the Chicago-based aircraft giant.

Under informal Senate procedures, one lawmaker can keep a bill from moving forward indefinitely. Although colleagues can theoretically attempt an override, such steps are rare in practice.