That prompted loud protests from Republican senators opposed to the plan.
They wanted help from senators for a number of issues they were pressing.
That review was prompted, in part, by questions from senators responsible for overseeing the program.
In contrast to its easy approval this week by the House, the legislation came under attack from senators of both parties.
The decision to moderate the airline tax came after pressure from senators whose states are home to some of the nation's biggest airlines.
"But people want to see a show of strength and leadership from Democratic senators."
The effort to woo the 7E7 was considerable, and included everyone from senators to local chamber of commerce officials.
Partisan attacks from senators hostile to the act should not decide her fate.
There were also suggestions that opposition was coming from senators of states where low-cost airlines are based.
For a majority, the government requires an additional seven votes from non-Labor senators.