A federal judge has rejected a bid by Schwartz, Simon, Edelstein & Celso to stop the Internal Revenue Service from issuing levies to its clients while the firm fights a $600,000 obligation in U.S. Tax Court.

The IRS began sending the notices to the Whippany firm’s clients after it defaulted in 2015 on a plan requiring installments of $20,000 per month toward its outstanding taxes. But U.S. District Judge Stanley Chesler denied the firm’s request for a preliminary injunction against the levies of clients, finding it failed to show that it is likely to succeed on the merits.