Reps. Christopher Shays, R-Conn., and Martin Meehan, D-Mass., had sued the FEC in federal court, contending the commission was interpreting the Bipartisan Campaign Reform Act in a manner that created a number of loopholes.
The core provisions of BCRA ban the use of "soft" money contributed outside federal limits directly in federal elections.
A number of FEC regulations implementing the act were found to be illegal, mostly in the definition of terms and in limits on "electioneering communications" -- broadcast advertisements -- leading up to an election.
The FEC filed a motion saying it was not required to follow the court's order pending appeal, and asked for a stay.
Tuesday, U.S. District Judge Colleen Kollar-Kotelly denied the stay, saying "the FEC has not established that the public interest" requires a stay."