Dr. Anthony Fauci has declined a request to appear voluntarily before a second Senate panel, according to a letter from his lawyer to Senator Ron Johnson. This comes after majority Republicans on the Homeland Security Committee voted along partisan lines last week to hold the former infectious disease expert in contempt.

In the letter, the lawyer for the former director of the National Institute of Allergy and Infectious Diseases said any effort to compel him to appear before a Senate subcommittee, after a contentious July 29 hearing, would be to “impermissibly harass or degrade Dr. Fauci for political purposes.”

During the July hearing on his handling of the COVID-19 pandemic, Fauci invoked the Fifth Amendment right against self-incrimination 100 times, prompting the Aug. 6 contempt vote and setting up a referral to the Justice Department for potential investigation.

Republican Senator Rand Paul of Kentucky, the committee chairman who pressed for the contempt finding, said the constitutional protection did not apply because President Joe Biden had issued a preemptive pardon to Fauci, so he did not need to be concerned about potential prosecution. Paul has long accused Fauci of misleading the public during the pandemic and has repeatedly called for him to be prosecuted and imprisoned.

Johnson, chairman of the subcommittee on investigations, had sought to open a parallel avenue of congressional investigation about Fauci’s role in responding to the COVID-19 pandemic, including the safety and efficacy of the COVID-19 vaccines.