The American Center for Law and Justice has filed a federal lawsuit on behalf of 25 conservative groups that say they were targeted by the IRS.

Jay Sekulow, the center’s chief counsel, said the lawsuit will show the IRS abuses went far above a couple “rogue agents,” as the Obama administration claims.

He has 15 IRS letters harassing conservative groups that were stamped with the signature of Lois Lerner, the IRS boss in charge of the tax-exempt office at the center of the scandal.

Meanwhile, White House spokesman Jay Carney says the White House is satisfied with the responsiveness of the IRS to congressional inquiries about its admission that the agency targeted for special scrutiny, organizations associated with the Tea Party and belief in limited, constitutional government. Carney’s statement comes just days after IRS official Lois Lerner refused to answer questions before a congressional hearing, invoking the Fifth Amendment.