Martin Totaro, former MoloLamken partner, recently joined DOJ civil from SEC DOJ faces small and large firms, and advocacy groups challenging OSHA rule (Reuters) - A former senior U.S. securities litigator who also is an ex-partner at prominent boutique firm MoloLamken is now leading the court defense of the Biden administration"s COVID-19 vaccination rule for large employers. U.S. Justice Department lawyer Martin Totaro this week filed appearance notices in federal appeals courts to oppose state and private challenges to a rule requiring employers with more than 100 workers to mandate vaccination or provide a testing and masking alternative. Totaro brings to the lead counsel role years of experience briefing and arguing cases at Washington, D.C.-based MoloLamken, widely known for its appellate and Supreme Court practice, and later at the U.S. Securities and Exchange Commission. Totaro joined the DOJ civil division last month from the securities agency. In a court filing on Wednesday in the New Orleans-based 5th U.S. Circuit Court of Appeals, Totaro said the Occupational Safety & Health Administration rule "will save thousands of lives and prevent hundreds of thousands of hospitalizations." The Biden administration said the rule will be enforced starting on Jan. 4. Totaro did not respond to a message seeking comment. DOJ is facing an array of advocacy groups and small and large law firms attacking the rule, which the 5th Circuit temporarily blocked on Nov. 7. "This challenged action is an extreme assertion of administrative power," Steve Lehotsky, partner at boutique Lehotsky Keller, said in a filing on Wednesday for the National Retail Federation and other trade groups. DOJ"s vaccine litigation team includes former Goldstein & Russell partner Sarah Harrington, now head of the civil appellate staff, and attorneys Michael Raab, Brian Springer and Adam Jed, who served on Robert Mueller III"s special counsel team. Labor Department lawyers including Seema Nanda, the agency solicitor, are working of counsel with the DOJ. For two years during the Trump administration, Totaro was on a detail from the SEC at the Justice Department. He was on the DOJ team that defended former Trump White House Counsel Donald McGahn in a subpoena fight with U.S. House Democrats. As an SEC lawyer, Totaro defended the agency"s administrative law judges in constitutional litigation and he argued in defense of broad liability for false statements under U.S. securities laws. Robert Heim of New York"s Tarter Krinsky & Drogin, who argued against Totaro in 2016 in the D.C. Circuit in an SEC case, said he showed a hallmark of appellate advocacy in his ability to "adjust to judges" questions that oftentimes are not expected."