A federal judge’s preliminary injunction that blocks funding for human embryonic stem cell research should not be put on hold while the U.S. Department of Justice challenges the decision on appeal, attorneys for two adult stem cell researchers said Tuesday in court papers.

The plaintiffs, including Drs. James Sherley and Theresa Deisher, won the injunction in August in the U.S. District Court for the District of Columbia. Justice attorneys want Chief Judge Royce Lamberth’s ruling stayed while the government fights the decision in the U.S. Court of Appeals for the D.C. Circuit. (Lamberth earlier denied the government’s request for a stay of his ruling.)

Last week, the appeals court issued an administrative stay, giving the court time to examine the merits of the Justice Department’s emergency motion for a stay. The Gibson, Dunn & Crutcher attorneys who are representing Sherley and Deisher on Tuesday urged the appeals court to deny the DOJ request.

“A stay pending appeal will result only in further injury to [the plaintiffs] and additional waste of taxpayer dollars being poured into an illegal, unethical, and scientifically speculative enterprise,” Gibson partner Thomas Hungar, co-chair of the firm’s appellate and constitutional law practice group, said in court papers.

The Gibson team, working with Washington’s Alliance Defense Fund and Fairfax-based Advocates International, said in the court papers that a stay pending appeal “would lead to a flight of federal dollars into [human embryonic stem cell] research,” hurting Sherley and Deisher and other National Institutes of Health grant applicants.

The plaintiffs’ lawyers said the NIH has an “ideological preference for spending as much federal money as practicable on illegal” human embryonic stem cell research. Federal money for such research, Hungar said, conflicts with federal law that forbids funding for research in which a human embryo is destroyed.

Justice lawyers on Sept. 8 asked for an emergency stay, saying that if the injunction is left in place it threatens the “immediate loss of ongoing medical research aimed at curing the most devastating illnesses afflicting Americans.” In court papers Tuesday, lawyers for Sherley and Deisher call the government’s claims “speculative” and said a delay “will not meaningfully affect the pace of scientific discovery.”

The D.C. Circuit has given the Justice Department until Sept. 20 to file a reply in support of the government’s effort to put on hold the preliminary injunction.

Mike Scarcella can be contacted at mscarcella@alm.com.